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NCERT Class 12 Computer Science Chapter 7 Networking and Open Source Concepts

NCERT Class 12 Computer Science Python Solutions for Chapter 7 :: Networking and Open Source Concepts

TOPIC-1

Communication TechnologiesVery Short Answer Type Questions (1 Mark each)

Question 1:Identify the Domain name and URL from the following:https://ift.tt/2Rc5dG8Answer:Domain name – income.inURL – https://ift.tt/2Rc5dG8.

Question 2:What is web hosting?Answer:Web hosting is the service that makes our website available to be viewed by others on the Internet. A web host provides space on its server, so that other computers around the world can access our website by means of a network or modem.

Question 3:Write two characterstics of Wi-Fi.Answer:

It is wireless network.

It is for short range.

Question 4:Which protocol is used to creating a connection with a remote machine?Answer:Telnet: It is an older internet utility that lets us log on to remote computer system. It also facilitates for terminal emulation purpose.

Question 1:Which protocol is used to create a connection to a remote machine? Give any two advantages of using optical fibers.Answer:Two advantage of using optical fibers are:

Capable of extremely high-speed.

No electromagnetic interference.

Extremely low attending.

Question 6:Expand the following:

GSM

GPRS

Answer:

GSM: Global System for Mobile Commu-nication.

GPRS: General Packet Radio Service.

Question 7:What is the difference between packet and message switching ?Answer:

Question 8:What is cloud computing?Answer:The sharing of compute resources (dedicated, time-shared, or dynamically shared servers) and related infrastructure components (load balncers, firewalls, network storage, developer tools, monitors and management tools) to facilitate the deployment and operation of web and network based applications. Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a net-work.

Question 9:Which type of network (out of LAN, PAN and MAN) is formed, when you connect two mobiles using Bluetooth to transfer a video?Answer:PAN

Question 10:Write one characterstic each for 2G and 3G mobile technologies.Answer:2G networks primarily involve the transmission of voice information, 3G technology provides the additional advantage of data transfer.

Question 11:What is the difference between Packet switching and circuit switching techniques?Answer:In circuit switching, a dedicated path exists from source to destination while in packet switching, there is no fixed path.

Question 12:Write two advantages of using an optical fibre cable over an Ethernet cable to connect two service stations, which are 200 m away from each other.Answer:Advantages of optical fibre:

Faster speed than ethernet

Lower attenuation

Question 13:Write one advantage of bus topology of network. Also illustrate how four (4) computers can be connected with each other using bus topology of network.Answer:Advantage (benefits) of linear Bus topology is that the cable length required for this topology is the least compared to the other networks.Bus Topology of Network:

Question 14:Give one suitable example of each URL and Domain Name.Answer:URL: http://waltons.inDomain Name: @gmail.com

Question 15:Write one advantage of star topology network? Also, illustrate how five (5) computers can be connected to each other using star topology of network.Answer:Advantage (benefits) of star toplogy:Easy to replace, install or remove hosts or other devices.

Question 16:What is the function of Modem?Answer:The function of modem is modulation and demo-dulation, means turn data into a format that can be transmitted via an audio link such as a phone line.

Question 17:Explain the purpose of a router.Answer:A router established connection between two networks and it can handle network with different protocols. Using a routing table, routers make sure that the data packets are travelling through the best possible paths to reach their destination.

Question 18:Name any two components required for net-working.Answer:

Repeater

Routers

Question 19:What are repeaters?Answer:A repeater is an electronic device that receives a signal and retransmits it at a higher level and/ or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.

Question 20:Mention one advantage of star topology over bus topology in networking?Answer:Simple to add more computers to network.

Question 21:Differentiate between packet swiching and message switching technique in network commu-nication.Answer:In packet switched network, data are transmitted in discrete units of potentially variable length blocks called packets, while in message switching mechanism, a node receives a message stores it until the appropriate route is free, then sends it along.

Question 22:Differentiate between Bus and Star topology of network.Answer:

Question 23:What is VoIP?Answer:Voice over Internet Protocol (VoIP) is one of a family of internet technologies, communication protocols, and transmission technologies for delivery of voice communications and multi-media sessions over internet protocol (IP) network, such as the internet.

Question 24:In networking, what is WAN? How is it different from LAN?Answer:WAN (Wide Area Network):A communication network that uses such devices as telephone lines, satellite, dishes, or radiowaves to span a larger geographic area which cannot be covered by a LAN.

Question 25:Define the term bandwidth. Give any one unit of bandwidth.Answer:Bandwidth is referred as the volume of information per unit of time that a transmission medium (like an internet connection) can handle.ORThe amount of data that can be transmitted in a fixed amount of time is known as bandwidth. For digital devices, the bandwidth is usually expressed in bits per second (bps) or bytes per second. For analog devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).

Question 26:What is the difference between LAN and MAN?Answer:LAN: It is Local Area Network. The diameter is not more than a single building.WAN: It is Metropolitan Area Network. LAN spans a few kms while MAN spans 5-50 km diameter and is larger than a LAN.

Question 27:What is the importance of URL in networking ?Answer:A Uniform Resource Locator (URL) is used to specify, where an identified resource is available in the network and the mechanism for retrieving it. A URL is also referred to as a web address. 1

Question 28:What was the role of ARPANET in the computer network?Answer:In 1969, ARPANET was set up by the American government for defence purpose. ARPANET stands for Advanced research Projects agency Network.

Question 29:Which of the following is not a unit for data transfer rate ?

bps

abps

gbps

kbps

Answer:(ii) abps

Question 30:Identify the type of topology from the following:

Each node is connected with the help of a single cable

Each node is connected with the help of independent cable with central switching.

Answer:

Bus topology

Star topology

Question 31:ABC International School is planning to connect all computers, each spread over a distance of 50 metres. Suggest an economic cable type having high speed data transfer to connect these computers.Answer:Optical fibre cable.

Question 32:Mahesh wants to transfer data within a city at very high speed. Write the wired transmission medium and type of network.Answer:Wired transmission medium – Optical fibre cable Type of network – MAN.

Question 33:Which device is used to connect all computers inside a lab?Answer:Hub

Question 34:Which device is used to connect all computers to the internet using telephone wire?Answer:RJ – 45. It is an eight wired connectors used to connect computers on a LAN.

Question 35:What is Wi-Fi Card?Answer:Wi-Fi cards are small and portable cards that allow the computer to connect to the internet through a wireless network. The transmission is through the use of radio waves.

Short Answer Type Questions

Question 1:Write any two differences between twisted pair and co-axial pair cable.Answer:

Question 2:Write one advantage of Bus Topology of network, also, illustrate how 4 computers can be connected with each other using star topology of network.Answer:Bus topology: Cable length required for his topology is the least compared to other networks.

Question 3:Explain any two switching techniques used in networking.Answer:Message Switching: It is similar to Post-office mailing system. A temporary link is established for one message transfer.Packet Switching: It is a form of store and forward switching system which stores the message as small packets at the switch nodes and then transmits it to the destination.

Long Answer Type Questions

Question 1:Write answer of the following:(a) Differentiate between PAN and LAN types of networks.(b) Which protocol helps us to transfer files to and from a remote computer ?(c) Write two advantages of 3G over 2G mobile telecommunication technologies in terms of speed and services.(d) Write two characteristics of Web 2.0(e) Write the basic difference between worm and Trojan Horse.(f) Categorize the following under client-side and server-side scripts category:

Jave Script

ASP

VB Script

JSP

(g)Intelligent Hub India is a knowledge community aimed to uplift the standard of skills and knowledge in the society. It is planning to setup its training centres in multiple towns and villages pan India with its head offices in the nearest cities. They have created a model of their network with a city, a town and 3 villages as given.As a network consultant, you have to suggest the best network related solution for their issues/problems raisedin (i) to (iv) keeping in mind the distance between various locations and given parameters.

Shortest distance between various locations:

Number of computers iinstalled at various locations are as follows:

Note:• In Villages, there are community centres, in which one room has been given as training center to this organiza¬tion to install computers.• The organization has got financial support from the government and top IT companies.

Suggest the most appropriate location of the SERVER in the YHUB (out of the 4 locations), to get the best and effective connectivity. Justify your answer.

Suggest the best wired medium and draw the cable layout (location to location) to efficiently connect vari¬ous locations within the YHUB.

Which hardware device will you suggest to connect all the computers within each location of YHUB?

Which server/protocol will be most helpful to conduct live interaction of Experts from Head office and people at YHUB locations?

Answer:1.(a)OR(b) FTP or Telnet or TCPFTP OR Telnet OR TCP(c) Speed

Faster web browsing.

Faster file transferService –

Better video clarity

Better security

OR(Any other correct advantage can be considered)

(d) Makes web more interactive through online social media.Supports easy online information exchange.Interoperability on the internet.Video sharing possible in the websites.(e)

(f)

(g)(i) YTOWNJustification

Since it has the maximum number of computers.

It is closet to all other locatios.

(ii) Optical Fiber

(iii) Switch or Hub(iv) Video conferencing or VoIP or any other correct service/protocol.

Question 2:Indian School, in Mumbai is starting up the network between its different wings. There are four Buildings named as SENIOR, JUNIOR, ADMIN and HOSTEL as shown below:The distance between various buildings is as follows:Number of Computers in Each Building :

Suggest the cable layout of connections between the buildings.

Suggest the most suitable place (i.e., building) to house the server of this school, provide a suitable reason.

Suggest the placement of the following devices with justification.

Repeater

Hub/Switch

The organisation also has inquiry office in another city about 50-60 km away in hilly region. Suggest the suitable transmission media to interconnect to school and inquiry office out of the following :

Fiber optic cable

Microwave

Radiowave

Answer:

Server can be placed in the ADMIN building as it has the maxium number of computer.

Repeater can be placed between ADMINand SENIOR building as the distance is more than 110 m.

Radiowaves can be used in hilly regions as they can travel through obstacles.

Question 3:Vidya Senior Secondary Public School in Nainital is setting up the network between its different wings. There are 4 wings named as SENIOR(S), JUNIOR(J), ADMIN(A) and HOSTEL(H).Distance between various wings are given below:

Suggest a suitable Topology for networking the computers of all wings.

Name the most suitable wing where the Server should be installed. Justify your answer.

Suggest where all should Hub(s)/Switch(es) be placed in the network.

Which communication medium would you suggest to connect this school with its main branch in Delhi ?

Answer:

Server should be in Wing S as it has the maxi-mum number of computers. 1

All Wings need hub/switch as it has more thanone computer.

Since the distance is more, wireless transmission would be better. Radiowaves are reliable and can travel through obstacles.

Question 5:

Which out ot three type of networks LAN. MAN and WAN, is to be used when an institute connects computers of two adjacent computer laboratories ?

What is the difference between HTTP and FTP?

What is the major difference between Message Switching and Packet Switching in networking?

What is the basic difference between DNS and URL?

Give two applications of web 2.0.

Categories the following under client side and Server-Side script category?

JSP

ASP

VBScript

Jave Script

Answer:(i) LAN (The ange is upto one KM)(ii) (iv)(v) Application of web 2.0

web hosting

web browsing

web Indexing

web searching

(vi) Client side Script

JSP

Java ScriptServer Side Scripts

ASP

VB Script

Question 6:Trine Tech Corporation (TTC) is a professional consultancy company. The company is planning to set up their new offices in India with its hub at Hyderabad. As a network adviser, you have to understand their requirement and suggest them the best available solutions. Their queries are mentioned as (i) to (iv) below.Physical Locations of the blocked of TTC

What will be the most appropriate block, where TTC should plan to install their server?

Draw a block to cable layout to connect all the buildings in the most appropriate manner for efficient communication.

What will be the best possible connectivity out of the following, you will suggest to connect the new setup of offices in Bangalore with its London based office:

Satellite Link

Infrared

Ethernet Cable

Which of the following device will be suggested by you to connect each computer in each of the buildings:

Switch

Modem

Gateway

Answer:

Finance block because it has maximumnumber of computers.

Satellite link

Switch

Question 7:G.R.K International Inc. is planning to connect its Bengaluru Office Setup with its Head Office in Delhi. The Bengaluru Office G.R.K. international Inc. is spread across and area of approx. 1 square kilometer, consisting of 3 blocks – Human Resources, Academics and Administration.You as a network expert have to suggest answers to the four queries (i) to (iv) raised by them.Notes : Keep the distance between blocks and number of computers in each block in mind, while providing them the solutions.

Suggest the most suitable block in the Bengaluru Office Setup, to host the server.Give a suitable reason with your suggestion.

Suggest the cable layout among the various blocks within the Bengaluru Office Setup forconnecting the Blocks.

Suggest a suitable networking device to be installed in each of the blocks essentially required for connecting computers inside the blocks with fast and efficient connectivity.

Suggest the most suitable media to provide secure, fast and reliable data connectivity between Delhi Head Office and the Bengaluru Office Setup.

Answer:

Human Resources because it has maximum number of computers.

Switch 1

Satellite link

Question 8:Rovenza Communications International (RCI) is an online corporate training provider company for IT related courses. The company is setting up their new compus in Kolkata. You as a network expert have to study the physical locations of various blocks and the number of computers to be installed. In the planning phase, provide the best possible answers for the queries (i) to (iv) raised by them.Block to Block Distances(in Mtrs.)Expected computers to be installed in each block

Suggest the most appropriate block, where RCI should plan to install the server.

Suggest the most appropriate block to block cable layout to connect all three blocks for efficient communication.

Which type of network out of the following is formed by connecting the computers of these three blocks?

LAN

MAN

WAN

Which wireless channel out of the following should be opted by RCI to connect to students from all over the world?

Infrared

Microwave

Satellite

Write two advantages of using open source software over proprietary software.

Which of the following crime(s) does not come under cybercrime?

Copying some important data from a computer without taking permission from the owner of-the data.

Stealing keyboard and mouse from a shop.

Getting into unknown person’s social networking account and start messaging on his behalf.

Answer:

Faculty Recording Block.

Star topology

LAN

Satellite connection

Advantages of open source over proprietary software:

Open source software’s source code is available, can be modified copied & distributed while propritary software can’t be change.

Open source is free while proprietary a paid.

Question 9:

Identify the type of topology on the basis ofthe following:

Since every node is directly connected to the server, a large amount of cable is needed which increases the installation cost of the network.

It has a single common data path connecting all the nodes.

Answer:

Star Topology

Bus Topology

(ii) Expand the following

VOIP

SMTP

Answer:

Voice Over Internet Protocol

Simple Mail Transder Protocol

(iii) Who is a hacker?

Answer:A computer enthusiast, who uses his computer programming skill to intentionally access a computer without authorization is known as hacker. A hacker accesses the computer without the intention of destroying data or maliciously harming the computer.(iv) The following is a 32 bit binary number usually represented as 4 decimal values, each representing 8 bits, in the range 0 to 255 (known as octets) separated by decimal points. 140.179.220.200What is it? What is its importance?Answer:It is an IP Address. It is used to identify the computers on a network.(v) Daniel has to share the data among various computes of his two offices branches situated in the same city. Name the network (out of LAN, WAN, PAN and MAN) which is being formed in this process.Answer:MAN(vi)Rehaana Medicos Center has set up its new center in Dubai. It has four buildings as shown in the diagram given below:

As a network expert, provide the best possible answer for the following queries:

Suggest a cable layout of connections between the buildings.

Suggest the most suitable place (i.e. building) to house the server of this organization.

Suggest the placement of the following device with justification:

Repeater (b) Hub/Switch

Suggest a system (hardware/software) to prevent unauthorized access to or from the network.

Answer:

Layout 1

The most suitable place / building to house the server of this organization would be building Research Lab, as this building contains the maximum number of computers.

Since the cabling distance between Accounts to Store is quite large, so a repeater would ideally be needed along their path to avoid loss of signals during the course of data flow in this route.

Firewall.

Question 10:

What is the difference between domain nameand IP address?

Write two advantages of using an optical fibre cable over an Ethernet cable to connect two service stations, which are 190 m away from each other.

Expertfa Professsional Global (EPG) is an online, corporate training provider company for IT related courses. The company is setting up their new campus in Mumbai. You as a network expert have to study the physical locations of various buildings and the number of computers to be installed. In the planning phase, provide the best possible answer for the

Building to Building distances (in Mtrs.)

Suggest the most appropriate building, where EPG should plan to install the server.

Suggest the most appropriate building to building cable layout to connect all three buildings for efficient communication.

Which type of network out of the following is formed by connecting the computers of these three buildings?

LAN

MAN

WAN

Which wireless channel out of the following should be opted by EPG to connect to students of all over the world?

Infrared

Microwave

Satellite

Answer:

Domain Name is alphanumeric addressof a resource over network IP address is a Numeric Address of a resource in a Network.Example:Domain Name 1www.Gabsclasses.comIP Address102.112.0.153

Optical fibre Advantages:

Faster Communication.

Free from electrical & Noise interference.

(a) Faculty Studio Building(b) Bus Topology(c) LAN(d) Satellite

Question 11:To provide telemedicine faculty in a hilly state, a computer network is to be setup to connect hospitals in 6 small villages (VI, V2, …, V6) to the base hospital (H) in the state capital. This is shown in the following diagram.

No village is more than 20 km away from the state capital.Imagine yourself as a computer consultant for this project and answer the following questions with justification:

Out of the following what kind of link should be provided to setup this network: Microwave link, Radio Link, Wired Link ?

What kind of network will be formed; LAN, MAN, or WAN ?

Many times doctors at village hospital will have to consult senior doctors at the base hospital. For this purpose, how should they contact them: using email, sms, telephone, or video conference ?

(b) Out of SMTP and POP3 which protocol is used to receive emails ?(c) What are cookies in the context of computer networks?(d) Rajeshwari is trying for on-line subscription to a magazine. For this she has filled in a form on the magazine’s web site. When the clicks submit button she gets a message that she has left e-mail field empty and she must fill it. For such checking which type of script is generally executed client side script or server-side script ?(e) Mention any one difference between free-ware and free software.

Answer:(a)

Radio Link

MAN

e-mail

(b) POP3(c) Cookies are files that store user information that is used to identify the user when he logs into the system.(d) Server-side script(e) Freeware is a software that has the user to get unlimited usage for. Free software may be free for a certain period only.

Question 12:Workalot Consultants are setting up a secured network for their office campus at Gurgaon for their day-to-day office and web-based activities. They are planning to have connectivity between three buildings and the head office situated in Mumbai. Answer the questions (i) to (iv) after going through the building positions in the campus and other details, which are given below :

Suggest the most suitable place (i.e., building) to house the server of this organization. Also give a reason to justify your suggested location.

Suggest a cable layout of connections between the buildings inside the campus.

Suggest the placement of the following devices with justification:

Repeater.

Switch.

The organization is planning to provide a high speed link with its head office situated in Mumbai using a wired connection. Which of the following cables will be most suitable for this job ?

Optical Fiber

Co-axial Cable

Ethernet Cable

Answer:

The most suitable place to install server is building “RED” because this building have maximum computer which reduce communication delay.

(a) Since the cabling distance between buildings GREEN, BLUE and RED are quite large, so a repeater each, would ideally be need along their path to avoid loss of signals during the course of data flow in there routes.

(b) In the layout a switch each, would be needed in all the buildings, to interconnect the group of cables from the different computers in each building.

(iv) Optical fiber

Question 13:Granuda Consultants are setting up a secured network for their office campus at Faridabad for their day to day office and web based activities. They are planning to have connectivity between 3 building and the head office situated in Kolkata. Answer the questions (i) to (iv) after going through the building positions in the campus and other details, which are given below:

Suggest the most suitable place (i.e., block) to house the server of this organization. Also give a reason to justify your suggested location.

Suggest a cable layout of connections between the buildings inside the campus.

Suggest the placement of the following devices with justification:

Repeater

Switch

The organization is planning to provide a high speed link with its head office situated in the KOLKATA using a wired connection. Which of the following cable will be most suitable for this job?

Optical Fibre

Co-axial Cable

Ethernet Cable

Answer:

The most suitable place to install server is building “JAMUNA” because this building have maximum computer which reduce the communication delay.

Cable layout. (Bus topology).

(a) Since the cabling distance between buildings GANGA and JAMUNA are quite large, so a repeater each, would ideally be needed along their path to avoid loss of signals during the course of data flow in these routes.(b) In the layout a switch each would be needed in all the building, to interco¬nnect the group of cables from the different computers in each building.

Optical fiber

Question 14:India Skills Hub is a skill development community which has an aim to promote the standard of skills in the society. It is planning to set up its training centres in multiple towns and villages Pan India with its head offices in the nearest cities. They have created a model of their network with a city ABC Nagar, a town (UVW town) and 3 villages.As a network consultant, you have to suggest the best network related solutions for their issues/ problems raised in (i) to (iv), keeping in mind the distances between various locations and other given parameters.

Note:– In Villagers, there are community centers, in which one room has been given as training entrer to this organization to install computers.– The organization has got financial support from the government and top Multinational Organizations.

Suggest the most appropriate location of the SERVER in the Cluster (out of the 4 locations), to get the best and effective connectivity. Justify your answer.

Suggest the best wired medium and draw the cable layout (location to location) to efficiently connect various locations within the Cluster.

Which hardware device will you suggest to connect all the computers within each location of

Which service/protocol will be most helpful to conduct live interactions of Expersts from Head Office and peole at all locations of Cluster?

Answer:

Best location for the server is UVW-TOWN, because it is approximately equidistant from the village P, Q and R.

For connectivity between UVW-TOWN to head office is optic Fiber and to connect the villages, P, Q and R with server at UVW- TOWN is co-axial cable.

The villages R Q and R can be connected with server at UVW-TOWN by a Hub and the head office is connected by a Bus topology.

Between head office and UVWTOWNwe recommend for Bus topology, so HTTP protocol and other terminal can be connected by UDP or FTP protocols.

Question 15:Mudra publishing is a group of companies engaged in publishing IT related books located in the hilly area of Shimla. The companies are located in four different, blocks whose layout is shown in the following figure. Answer the questions (i) to (iv) with the relevant justifi-cations.Mudra publishing

Distance between various Blocks :

Block A to Block C is 50 m

Block A to Block D is 100 m

Block B to Block C is 40 m

Block B to Block D is 70 m

Block C to Block D is 125 mNumber of Computers

Block A is 25

Block B is 50

Block C is 20

Block D is 120

Suggest a suitable network topology between the blocks.

Which is the most suitable block to house the server of this organization?

Suggest the placement of the following devices with justification

Repeater

Switch

The organization is planning to link the whole blocks to its marketing Office in Delhi. Since cable connection is not possible from Shimla, suggest a way to connect it with high speed.

Answer:

Suitable topology is bus topology.

The most suitable block for hosting server is BLOCK-D because this block has maximum number of computers.Mudra Publishing

Switch is a device used to segment network into different sub-networks so switch will exist in all the blocks. Since distance between BLOCK-D and BLOCK-C is large so repeater will be install between BLOCK-D and BLOCK-C.

The most economic way to connect it with a reasonable high speed would be the use radiowave transmission, as they are easy to install, can travel long distance and penetrate buildings easily, so they are used for communication, both indoors and outdoors. Radiowaves also have the advantage of being omni-directional. They can travel in all the directions from the source, so that the transmitter and receiver do not have to be carefully aligned physically.

TOPIC-2Network Security and Web ServiceVery Short Answer Type Questions(1 Mark each)

Question 1:Define firewall.Answer:A system designed to prevent unauthorized access to or from a private network is called firewall, it can be implemented in both hardware and software or combination of both.

Question 2:Write any two examples of Server side Scripts.Answer:

ASP

PHP

Question 3:What is the difference between E-mail & chat?Answer:

Chat occurs in near real time, while E-mail doesn’t.

Chat is a 2-way communication which require the permission of both parties, while E-mail is a 1-way communication.

Question 4:Write names of any two popular open source software, which are used as operating systems.Answer:

Kernels

Unix

Linux

Question 5:What is the difference between video conferencing and chat.Answer:In conference, we can include more than one person and it allows text video and audio while chat is one-to-one communication.

Question 6:Expand the following abbreviations :

HTTP

VOIP

Answer:

HTTP-Hyper Text Transfer Protocol.

VOIP-Voice Over Internet Protocol.

Question 7:What is the difference between HTTP and FTP?Answer:Hyper Text Transfer Protocol deals with Transfer of Text and Multimedia content over internet while FTP (File Transfer Protocol) deals with transfer of files over the internet.

Question 8:What out of the following, will you use to have an audio-visual chat with an expert sitting in a far-away place to fix-up a technical issue ?

VoIP

FTP

Answer:(i) VoIP 1

Question 9:Name one server side scripting language and one client side scripting language.Answer:Client Side :

JAVASCRIPT

VBSCRIPTServer Side

ASP

JSP

Question 10:Which out of the following comes under cyber crime ?

Operating someone’s internet banking account, without his knowledge.

Stealing a keyboard from someone’s computer.

Working on someone’s Computer with his/ her permission.

Answer:(i) Operating someone’s internet banking account, without his knowledge.

Question 11:Name two proprietary software along with their application.Answer:

MS-Office – All office applications MS-Word, MS-Excel, MS-PowerPoint.

Visual Studio – Visual Basic, Visual C+ +software for application development.

Question 12:Out of the following, identify client side script (s) and server side script (s).

ASP

Javascript

VBScript

JSP

Answer:Server side scripting

ASP

JSPClient side scripting

Javascript

VBscript Vi

Question 13:Compare open source software and proprietary software.Answer:One need an authorized license paid in order to use this proprietary software while open sourcesoftware can be used by anybody and are usually free. One can use this software for their personal use. After giving any notation or code in this type one cannot change the code or modify it.

Question 14:Differentiate between XML and HTML.Answer:

Question 15:What is WEB 2.0 ?Answer:Web2.0 refers to the new generation of web based services and communities characterised by participation, collaboration and sharing of information among users online.

Question 16:Which of the following is/are not a client side script:

VB Script

Java Script

ASP

PHP ?

Answer:(iii) ASP and(iv) PHP are not client side scripts.

Question 17:If someone has hacked your website, to whom you lodge the complaint ?Answer:The complaint has to be lodged with the police under IT Act.

Question 18:What do you mean by IP address? How is it useful in computer security ?Answer:An Internet Protocol (IP) address is a numerical identification and logical address that is assigned to devices connected in a computer network.An IP address is used to uniquely identify devices on the internet and so one can quickly know the location of the system in the network. 1

Question 19:What do you mean by spam mails ? How can you protect your mailbox from spams ?Answer:Spam mails, also known as junk e-mail, is a subset of spam that involves nearly identical messages sent to numerous recipients by e-mail.We can protect our mailbox from spams by creating appropriate filters.

Question 20:When do you prefer XML over HTML and why ?Answer:The first benefit of XML is that because you are writing your own markup language, you are not restricted to a limited set of tags defined by proprietary vendors.Rather than waiting for standards bodies to adopt tag set enhancements (a process which can take quite some time), or for browser companies to adopt each other’s standards with XML, you can create your own set of tags at your own place.

Question 21:How does firewall protect our network ?Answer:A firewall is a part of a computer system or network, that is designed to block unauthorized access while permitting authorized communi-cations. It is a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all (in and out) computer traffic between different security domains based upon a set of rules and, other criteria. 1

Question 22:Compare freeware and shareware.Answer:Freeware, the name derived from the words “free” and “software”. It is a computer software that is available for use at no cost or for an optional fee. Freeware is generally proprietary software available at zero price, and is not free software. The author usually restricts one or more rights to copy, distribute, and make derivative works of the software.Shareware is usually offered as a trial version with certain features only available after the license is purchased, or as a full version, but for a trial period. Once the trial period has passed, the program may stop running until a license is purchased. Shareware is often offered without support, updates, or help menus, which only become available with the purchase of a license. The words “free trial” or “trial version” are indicative of shareware.

Question 23:How trojan horses are different from worms? Mention any one difference.Answer:A trojan horse is a term used to describe malware that appears to the user, to perform a desirable function but, in fact, facilitates unauthorized access, to the user’s computer system.A computer worm is a self-replicating computer program. It uses a network to send copies of itself to the other nodes (computers on the network) and it may do so without any user intervention.

Question 24:Give the full form of :

FOSS

HTTP

Answer:

FOSS : Free Open Source Software.

HTTP : Hyper Text Transfer Protocol.

Question 25:What is the difference between trojan horse and virus in terms of computers ?Answer:A trojan, sometimes referred to as a trojan horse, is non-self-replicating malware that appears to perform a desirable function for the user but instead facilitates unauthorized access to the user’s computer system. The term is derived from the trojan horse story in greek mythology.A computer virus is a computer program that can copy itself and infact a computer. A true virus can only spread from one computer to another.The chief difference between a trojan horse and a virus is that a trojan horse does not replicate itself. A virus does. 1

Question 26:Which term we use for a software/hardware device, which is used to block, unauthorized access while permitting authorized communi¬cations. This term is also used for a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all (in and out) computer traffic between different security domains based upon a set of rules and other criteria.Answer:Firewall.

Question 27:Write the full forms of the following:

GNU

XML

Answer:

GNU stands for “GNU’s Not Unix”

XML stands for “Extensible Markup Language”.

Question 28:Expand the following terminologies:

GSM

WLL (IMP)

Answer:

GSM: Global System for Mobile Communication

WLL: Wireless Local Loop.

Question 29:Name some cyber offences under the IT Act.Answer:

Tampering with computer source documents

Hacking.

Publishing of information which is obscenein electronic form.

Question 30:What are the three ways of protecting intellectual property ?Answer:

Patents

Copyrights

Trademark

Question 31:When a user browses a website, the web server sends a text file to the web browser. What is the name of this?Answer:Cookies.

Short Answer Type Questions

Question 1:Define the following:

Firewall

VoIE

Answer:

Firewall: A system designed to preventunauthorized access to or from a private network is called firewall, it can be implemented in both hardware and software or combination of both.

VoIP: Voice-over-Internet Protocol(VoIP) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.

Question 2:Give the full form of the following terms.

XML

FLOSS

HTTP

FTP

Answer:

XML: Extensible Markup Language.

FLOSS: Free-Libre Open Source Software.

HTTP: Hyper Text Transfer Protocol.

FTP: File Transfer Protocol.

Question 3:Differentiate between WORM and VIRUS in Computer terminology.Answer:VIRUS directly effects the system by corrupting the useful data. A computer virus attaches itself to a program or file enabling it to spread from one computer to another.A WORM is similar to a virus by design is considered to be subclass of a virus. Worm spread from computer to computer, but unlike a virus, it has the capability to travel without any human action. 2

Question 4:Expand the following

GSM

GPRS.

Answer:

GSM: Global System for Mobile Communi-cation.

GPRS: General Packet Radio Service.

Question 5:Expand the following abbreviations :

HTTP

VOIP

Answer:

HTTP: Hyper Text Transfer Protocol.

VOIP: Voice Over Internet Protocol.

Question 6:Give the full form of :

FOSS

HTTP

Answer:

FOSS: Free Open Source Software.

HTTP: Hyper Text Transfer Protocol.

Question 7:Write the full forms of the following :

GNU

XML

Answer:

GNU: GNU’s Not Unix

XML: Xtensible Markup Language.

Question 8:Expand the following terminologies :

GSM

WLL

Answer:

GSM: Global System for Mobile Communi-cation

WLL: Wireless Local Loop.

Question 9:Give the full forms of the following terms :

CDMA

TDMA

FDMA

Answer:

CDMA: Code Division Multiple Access

TDMA: Time Division Multiple Access

FDMA: Frequency Division Multiple Access

Question 10:Expand the following abbreviations :

FTP

TCP

SMTP

VOIP

Answer:

FTP: File Transfer Protocol

TCP: Transmission Control Protocol.

SMTP: Simple Mail Transfer Protocol.

VOIP: Voice Over Internet Protocol

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NCERT Class 12 Computer Science Chapter 6 Boolean Algebra

NCERT Class 12 Computer Science Python Solutions for Chapter 6 :: Boolean Algebra

TOPIC- 1

Basics of Boolean AlgebraVery Short Answer Type Questions (1 Mark each)

Question 1:Express the OR operator in terms of AND and NOT operator.Answer:

Question 2:Answer:(a) x+x’=1-Complementary law(b) xy+x=x & absorption law

Question 3:Which gates are known as universal gates? Why?Answer:Universal gates are the ones which can be used for implementing any gate like AND, OR and NOT or any combination of these basic gates. NAND and NOR gates are universal gates.

Question 4:State and verify Associative law using Truth Table.Answer:Associative Law: This law states that:(A+B)+C=A+(B+C)(A.B).C=A.(B.C)Proof:From the above tables,(A+B)+C=A+(B+C)Similarly, we can prove,A.(B.C)=(A.B).C

Question 5:Draw the equivalent logic circuit for the following Boolean experession :Answer:

Short Answer Type Questions

Question 1:State and define principle of duality. Why is it so important in Boolean Algebra?Answer:Principle of duality: Duality principle states that from every boolean relation another boolean relation can be derived by:

Changing each OR sign (+) to an AND sign (•)

Changing each AND sign (.) to an OR sign (+)

ex : Dual of A + A’B = A . (A1 + B)

Importance in Boolean Algebra: The principle of duality is an important concept in Boolean algebra, particularly in proving various theorems. The principle of duality is used extensively in proving Boolean algebra theorem. Once we prove that an expression is valid, by the principle of duality, its dual is also valid. Hence, our effort in proving various theorems is reduced to half.

Question 2:Write the equilent boolean expression for the following logic circuit.Answer:((X’.Y’)’+(X’.Y’)’)’

Question 3:Write the equilent boolean expression for the following logic circuit.Answer:

Question 4:Write the equivalent boolean expression for the following logic circuit:Answer:

Question 5:Name the law shown below & verify it using a truth table.Answer:This law is called “Absorption Law” also reffered as redundance law.

Question 6:Obtain the Boolean Expression for the logic circuit shown below.Answer:

Question 7:Verify the following using truth table:(i) X+0=X(ii) X+x’=1Answer:

Question 8:Obtain the Boolean Expression for the logic circuit shown below.

Answer:

Question 9:State Demorgan’s law. Verify one of them using truth tableAnswer:

Question 10:Draw a logic circuit for the Boolean expressionAnswer:

Question 11:Obtain the boolean expression for the logic circuit shown below:Answer:

Question 12:Verify the following using Boolean Lawas:X+Z=X+X’Z+Y.ZAnswer:

Question 13:Verify the following using Boolean Lawas:A+C=A+A’.C+B.CAnswer:

Question 14:Obtain the Boolean Expression for the logic circuit shown below:Answer:

Question 15:Verify the following using truth table:(i) X.X’=0(ii) X+1=1Answer:

Question 16:Write the equivalent boolean expression for the following logic circuit:Answer:

Question 17:Answer:Distribution law: This law states that(i) x(y+z)=x.y+x.z(ii) x+yz=(x+y)(x+z)Noe let us prove using truth table.

Question 18:Name the law shown below & verify it using a truth table.A+B.C=(A+B).(A+C).Answer:This law is called “Distribute Law”.Prove ny Truth table

Question 19:Write the POS form of a Boolean Function F, which is represented in a truth table as follows:Answer:(P+Q+R).(P’+Q+R).(P’+Q’+R)

Question 20:Write the Boolean Expression for the result of the Logic Circuit as shown below:Answer:The boolean expression is :I=[(A+b).(A’+C’)].(B+C)

Question 21:Derive a Cannonical POS expression for a Boolean function G, represented by the following truth table:Answer:

Question 22:Correct the following boolen statements:Answer:

Question 23:Derive a Cannonical SOP expression for a Boolean function G, represented by the following truth table:Answer:

Question 24:Derive a Canonical POS expression for a Boolen funtion F, represented by the following truth table:Answer:

Question 25:Write the Boolen Expression for the result of the Logic Circuit shown below:Answer:C=P.Q’+P.R+Q.R’

Question 26:Verify the following using Boolen LawsP’+Q’.R=P’.Q’.R’+P’.Q.R’+P’.Q.R+P’.Q’.R+P.Q’.RAnswer:

Question 27:Verify the following using Boolen Laws x’+y’z = x’y’z’+x’y’z’+x’yz+x’y’z+xy’zAnswer:

Question 28:State and prove De-Morgan’s laws in boolean algebra.DeMorgan’s theorem states that:(i) (X+Y)’=X’.Y’(ii) (X.Y)’=X’+Y’Answer:Now ,let us proove using truth table

Question 29:Write the equivalent boolean expression for the following logic circuit:Answer:

Question 30:Verify the following using truth table:Answer:

Question 31:Write the equivalent boolean expression for the following logic circuit:Answer:F=(X+Y’).(X+Z’)

Question 32:Verify the following using truth table:X+Y.Z=(X+Y).(X+Z)Answer:

Question 33:Write the equivalent boolean expression for the following logic circuit:Answer:PQ’+PR’=P(Q’+R’)

Question 34:State abd cerify De-Morgan’s laws algebraicallyAnswer:

Question 35:Write the equivalent boolean expression for the following logic circuit:Answer:F(P,Q)=(P’+Q).(P+Q’)

Question 36:State and algebraically verify Absorption lawAnswer:

Question 37:Write the equivalent boolean expression for the following logic circuit:Answer:F(U,V)=(U’+V).(U+V’)

Question 38:Represent the expression X’.Y+Y’.Z+Z’X using NAND gatesAnswer:

Question 39:Write the equivalent expression for the following logical circuit:Answer:F=A’.B’+B’C’

Question 40:Verify the following algebraically.(A’+B’).(A+B)=A’.B+A.B’Answer:

Question 41:Write the equivalent boolean expression for the following logic circuit:Answer:Y=(P+Q’).(Q+R’)

Question 42:Verify the following algebrically:X’.Y+X.Y’=(X’+Y’).(X=Y)Answer:

Question 43:Write the equivalent boolean expression for the following logic circuit:Answer:(U’+V).(V’+W)

Question 44:Answer:

TOPIC-2Karnaugh Map Minimization and Applications of Boolean AlgebraVery Short Answer Type Questions

Question 1:Convert the following Boolean expression into its equivalent Canonical Sum of Products form (SOP):(U + V + W)(U+V + W’)(U’+V + W) (U’ + V’ + W’ )Answer:

Question 2:Write Product of Sum expression of the function F (a, b, c, d) from the given truth table.Answer:

Question 3:Write the Sum of Product form of the function F(P, Q, R) for the following truth table represen¬tation of F :Answer:

Question 4:Write the Product of Sum form of the function F(X, Y, Z) for the following truth table representation of F :Answer:

Question 5:Write the Product of Sum form of the function G(U, V, W) for the following truth table representation of G :Answer:

Question 6:Write the Product of Sum form of function G(U, V, W) for the following truth table representation of G :Answer:

Question 7:Write the Sum of Product form of the function F(A, B, C) for the following truth table reprsen- tation of F.Answer:

Question 8:Write the SOP form of a boolean function F, which is represented in a truth table as follows:Answer:F(X,Y,Z)=X’.Y’Z’+X’.Y’.Z’+X.Y’.Z’+X.Y.Z

Question 9:Write the POS form of boolean function G, which is represented in a truth table as follows :Answer:G(A,B,C)=(A+B+C).(A+B’+C’).(A’+B+C).(A’+B+C’)

Question 10:Write the SOP form of a boolean function F, which is represented in a truth table as follows :Answer:SOP form is given byX’Y’Z’ + X’Y’Z + X’YZ + XY’Z’ + XYZ

Question 11:Write the POS form of a boolean function F, which is represented in a truth table as follows :

Answer:(A + B + C). (A+B’ + C’).(A’ + B + C’). (A’ + B’ + C)

Question 12:Write the SOP form of a boolean function F, which is represented in a truth table as follows :Answer:F=(0,3,6,7)So, SOP form of F isF = (U’.V’W’) + (U’.VW) + (U.VW’) + (U.VW)

Question 13:Write the POS form of a boolean function F, which is represented in a truth table as follows :Answer:F (U, V, W) = (U + V + W’).(U+V’+W’). (U’+V+W’)

Question 14:Write the SOP form of a Boolean function F, which is represented in a truth table as follows :

Answer:G (P, Q, R) = P’QR’ + PQ’R’ + PQR’ + PQR

Question 15:Write the POS form of a boolean function H, which is represented in a truth table as follows :Answer:H (x, y, z) = (x + y + z’). (x’ + y + z’) . (x’ + y’ + z)

Question 16:Write the SOP form of a boolean function G, which is represented in a truth table as follows :

Answer:G (R Q, R) = P’QR’ + P’QR + PQ’R’ + PQR’ + PQR

Question 17:Write the POS form of a boolean function G, which is represented in a truth table as follows :Answer:G(U. V W) = (U + V + W). (U’ + V + W’). (U’ + V’ + W)

Question 18:Write the POS form of a boolean function F, which is represented in a truth table as follows :

Answer:F(U, V, W) = (U + V + W’) . (U + V’ + W’) . (U’ + V + W’)

Question 19:Reduse the following Boolean Expression to its simplest form using K-Map :Answer:

Question 20:Write the SOP form of a Boolean function G, which is represented in a truth table as follows :Answer:G(P, Q, R) = P’.Q.R’ + PQ’.R’ + EQ.R’ + EQ.R

Question 21:Write the POS equivalent of ABC + AB’C’ + ABC’+ A’B’CAnswer:

Short Answer Type questions-II

Question 1:Obtain the minimal SOP form for the following Boolean expression using K-MapAnswer:

Question 2:Reduce the following Boolean expression using K-Map:F(A,B,C,D) = π(0,1,2,4,5,6,8,10)Answer:

Question 3:Reduce the following Boolean Expression using K-Map:Answer:

Question 4:Reduce the following Boolean Expression using K-Map:Answer:

Question 5:Reduce the following Boolean Expression using K-Map:Answer:

Question 6:Reduce the following Boolean Expression using K-Map:Answer:

Question 7:Reduce the following Boolean Expression using K-Map:Answer:

Question 8:Reduce the following Boolean Expression using K-Map:Answer:

Question 9:Reduce the following Boolean Expression using K-Map:Answer:

Question 10:Reduce the following Boolean Expression using K-Map:Answer:

Question 11:Reduce the following Boolean Expression using K-Map:F(A,B,C,D)=S(0,1,3,5,6,7,11,13,14,15)Answer:

Question 12:Reduce the following Boolean Expression using K-Map:Answer:

Question 13:Simplify the following boolean expression using K-Map:Answer:

Question 14:Reduce the following boolean expression using K-Map:Answer:

Question 15:Answer:

Question 16:Reduce the following Boolean Expression using K-Map:Answer:

Question 17:Reduce the follwing Boolean Expression using K-Map:Answer:

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NCERT Class 12 Computer Science Chapter 4 Database Concepts

NCERT Class 12 Computer Science Python Solutions for Chapter 4 :: Database Concepts

Short Answer Type Questions-I

Question 1:Observe the following PARTICIPANTS and EVENTS table cerefully and write the name of the RDBMS operation which will be used to produce the output as shown in RESULT? Also, find the Degree and Cardinality of the RESULT.

Answer:Cartesian ProductDegree — 4Cardinality = 6

Question 2:Define degree and cardinality. Also, Based upon given table write degree and cardinality.Answer:Degree is the number of attributes or columns present in a table.Cardinality is the number of tuples or rows present in a table.Patients Degree = 4Cardinality = 5

Question 3:Observe the following table and answer the parts (i) and (ii):

In the above table, can we have Qty as primary key.

What is the cardinality and degree of the above table?

Answer:

We cannot use Qty as primary key because there is a duplication of values and primary key value cannot be duplicate.

Degree =4Cardinality = 5

Question 4:Explain the concept of union between two tables, with the help of appropriate example.Answer:The union operation denoted by ‘U’ combines two or more relations. The resultant of union operation contain tuples that are in either of the table or in both tables.

Question 5:Observe the following STUDENTS and EVENTS tables carefully and write the name of the RDBMS operation which will be used to produce the output as shown in LIST table? Also, find the degree and cardinality of the table.Answer:Cartesian ProductDegree = 4Cardinality = 6

Question 6:Observe the following MEMBER and ACTIVITY tables carefully and write the name of the RDBMS operation, which will be used to produce the output as shown in REPORT? Also, find the Degree and Cardinality of the REPORT.

Answer:Join operation or MEMBER U ACTIVITYDegree of Report = No of columns(No of Attributes) = 3Candinality Report = No of Rows(No of tuples) = 6

Question 7:Observe the table ‘Club’ given below:

What is the cardinality and degree of the given table?

If a new column Contact_No has been added and three more members have joined the club then

Answer:

Cardinality = 4 Degree = 5

Cardinality = 7

Degree = 6

Question 8:What do you understand by Union & Cartesian product in the relational algebra?Answer:Union of R ans S :The Union of two relations is a relation that includes all the tuples that are either in R or in S or in both R and S. Duplicate tuples are eliminated.The Union is an operator which works on two how sets. It combines the tuples of one relation with all the tuples of the other relation such that there is no duplication.

Cartesian Product: The cartesian product is an operator which works on two sets. It combines the tuples of one relation with all the tuples of the other relation.

Example: Cartesian Product

Question 9:Differentiate between the Alternate key of a table with the help of an example.Answer:Primary Key: A primary key is a value that can be used to identify a unique row in a table .Alternate Key: An alternate key is any candidate key which is not selected to be the primary keyExample:

So, (Bank Account Number, Aadhaar Number) are candidate keys for the table.Aadhaar Number — Primary keyBank Account Number — Alternate key

Question 10:Explain the concept of candidate key with the help of an appropriate example.Answer:Candidate key is a column or set of columns that can help in identifying records uniquely.Example, consider a Table STUDENT.Here, AdmnNo & Roll No define Table uniquely.Hence, they are candiadate keys

Question 11:What do you understand by degree & cardinality of a Table ?Answer:Degree refers to the number of columns in a table.Cardinality refers to the number of rows.

Question 12:Observe the following table and answer the part (i) and (ii) accordingly.

In the above table, can we take Mno as Primary key ? (Answer as [Yes/No] only.) Justify your answer with a valid reason.

What is the degree and the cardinality of the above table?

Answer:

Degree = 4Cardinality = 5[Hint: Because Pencil and Eraser are having the same Mno = 2. Primary key needs to be unique]

Question 13:Give a suitable example of a table with sample data and illustrate Primary and Candidate keys in it.Answer:A table may have more than one such attribute or a group of attribute that identifies a row/ tuple uniquely, all such attribute(s) are known as Candidate keys. Out of the Candidate keys, one is selected as Primary key.Id = Primary key Id and Qty = Candidates Keys

Question 14:What do you understand by selection and projection operations in the relational algebra?Answer:Projection (n): In relational algebra, projection is a unary operation. The result of such projection is defined as the set obtained when the components of the tuple R are restricted to the set {a1…,an} – it discards (or exculdes) the other attributes.Selection (): In relational algebra, a selection is a unary operation written as (R) or (R) where:

a and b are attribute names

i is a binary operation in the set

v is a value constant

R is a relation

The selection (R) selects all those tuples in R for which i holds between the a atribute and the b attribute.

Example: Selection and Projection

Question 15:What do you understand by Primary key and Candidate keys.Answer:An attribute or set of attributes which are used to identify a tuple uniquely is known as primary key. If a tuple has more than one such attribute which identify a tuple uniquely, than all such attributes are known as candidate keys.

Question 16:What is relation? Define the relational data model.Answer:A relation is a table having atomic values, unique row, and unordered rows and columns. The relational model represent data and relationship among data by a collection of tables known as relation, each of which has a number of columns with unique names.

Question 17:Define domain with respect to database. Give an example.Answer:A domain is a pool of values from which the actual values appearing in a given column are drawn.For example: The values appearing in the Supp# column of both the suppliers table and the Shipment table are drawn from the same domain.

Question 18:Expand the following:

SQL

DBMS

Answer:

SQL – Structured Query Language.

DBMS – Data Base Management System.

Question 19:What do you understand by candidate keys in a table? Give a suitable example of candidate keys from a table containing some meaningful data.Answer:Candidate key: A candidate key is one that can identify each row of a table uniquely. Generally, a candidate key becomes the primary key of the table. If the table has more than one candidate key, one of them will become the primary key, and the rest are called alternate keys.Example:Question 20:What are all the domain names possible in gender ?Answer:Male and Female

Question 21:A table ‘customer’ has 10 columns but no row. Later, 10 new rows are inserted and 3 rows are deleted in the table. What is the degree and cardinality of the table customer.Answer:Degree = 10 [no. of cols]Cardinality = 10-3 = 7 [no. of rows]

Question 22:A table ‘student’ has 3 columns and 10 rows and another table ‘student 2’ has the same columns as student but 15 rows. 5 rows are common in both the tables. If we take union, what is the degree and cardinality of the resultant table ?Answer:Degree = 3Cardinality = 30 (20 + 15 – 5)

Question 23:A table ‘student’ has 4 columns and 10 rows and ‘student 2’ has 5 columns and 5 rows. If we take cartesian product of these two tables, what is the degree and cardinality of the resultant table ?Answer: Degree = 4 x 5 = 20 [no. of columns]Cardinality = 10 x 5 = 50 [no. of rows]

Question 24:In the following 2 tables, find the union value of Student 1 and Student 2.Answer:

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NCERT Class 12 Computer Science Chapter 5 Structured Query Language

NCERT Class 12 Computer Science Python Solutions for Chapter 5 :: Structured Query Language

Short Answer Type Questions

Question 1:Write queries for (i) to (iv) and find ouputs for SQL queries (v) to (viii), which are based on the tables.

Table : VEHICLE

Note:

PERKS is Freight Charges per kilometer.

Km is kilometers Travelled

NOP is number of passangers travelled in vechicle.

To display CNO, CNAME, TRAVELDATE from the table TRAVEL in descending order of CNO.

To display the CNAME of all customers from the table TRAVEL who are travelling by vechicle with code Vo1 or Vo2

To display the CNO and CNAME of those customers from the table TRAVEL who travelled between ‘2015-1231’ and ‘2015-05-01’.

To display all the details from table TRAVEL for the customers, who have travel distacne more than 120 KM in ascending order of NOE

SELECT COUNT (*), VCODE FROM TRAVEL GROUP BY VCODE HAVING COUNT (*) > 1;

SELECT DISTINCT VCODE FROM TRAVEL :

SELECT A.VCODE, CNAME, VEHICLETYPE FROM TRAVEL A, VEHICLE B WHERE A. VCODE = B. VCODE and KM < 90;

SELECT CNAME, KM*PERKM FROM TRAVEL A, VEHICLE B WHERE A.VCODE = B.VCODE AND A. VCODE ‘V05’;

Answer:

Question 2:Consider the following tables SCHOOL and ADMIN and answer this question :Give the output the following SQL queries :

Select Designation Count (*) From Admin Group By Designation Having Count (*) <2;

SELECT max (EXPERIENCE) FROM SCHOOL;

SELECT TEACHER FROM SCHOOL WHERE EXPERIENCE >12 ORDER BY TEACHER;

SELECT COUNT (*), GENDER FROM ADMIN GROUP BY GENDER;

Answer:

Question 3:Write SQL qureries for (i) to (iv) and find outputs for SQL queries (v) to (viii), which are based on the tables TRANSPORT and TRIE

Note:

PERKS is Freight Charages per kilometer

TTYPE is Transport Vehicle Type

Note:

NO is Driver Number

KM is Kilometer travelled

NOP is number of travellers travelled in vehicle

TDATE is Trip Date

To display NO, NAME, TDATE from the table TRIP in descending order of NO.

To display the NAME of the drivers from the table TRIP who are traveling by transport vehicle with code 101 or 103.

To display the NO and NAME of those drivers from the table TRIP who travelled between ‘2015-02-10’ and ‘2015-04-01’.

To display all the details from table TRIP in which the distance travelled is more than 100 KM in ascending order of NOP

SELECT COUNT (*), TCODE From TRIPGROUP BY TCODE HAVNING COUnT (*) > 1;

SELECT DISTINCT TCODE from TRIP;

SELECT A.TCODE, NAME, TTYPEFROM TRIP A, TRANSPORT BWHERE A. TCODE = B. TCODE AND KM < 90;

SELECT NAME, KM *PERKMFROM TRIP A, TRANSPORT BWHERE A. TCODE = B. TCODE AND A. TCODE = 105′;

Answer:

SELECT NO, NAME, TDATE FROM TRIP ORDER BY NO;

SELECT NAME FROM TRIPWHERE TCODE = 101 OR TCODE = 103;

SELECT NO AND NAME FROM TRIPWHERE ‘2015-02-10’ < TDATE < ‘2015-04-01’;

SELECT NO, NAME, TDATE, KM, TCODE FROM TRIPWHERE KM >100 ORDER BY NOP;

TO DISPLAY THE MORE THAN ONE COUNT OF TCODE FROM THE TABLE TRIP

TO DISPALY SEPERATE TCODE OF TABLE TRIP

TO DISPAY THE NAME AND CODE OF THOSE TRANS PORTERS, WHO HAVE TRAVELLED MORE THAN 90 KMS.

TO DISPLAY THE NAME AND EXPENDITARE OF A TRANSPORTER WHO HAVE TCODE AS 105.

Question 4:Write SQL query to add a column total price with datatype numeric and size 10, 2 in a table product.Answer:ALTER TABLE PRODUCT ADD TOTAL PRICE NUMBER (10,2).

Question 5:Sonal needs to display name of teachers, who have “0” as the third character in their name. She wrote the following query.SELECT NAME FROM TEACHER WHERE NAME = “$$0?”;But the query is’nt producing the result. Identify the problem.Answer:The wildcards are incorrect. The corrected query is SELECT NAME FROM TEACHER WHERE NAME LIKE ‘_ _0%’.

Question 6:Deepika wants to remove all rows from the table BANK. But he needs to maintain the structure of the table. Which command is used to implement the same?Answer:DELETE FROM BANK.

Question 7:While creating table ‘customer’, Rahul forgot to add column ‘price’. Which command is used to add new column in the table. Write the command to implement the same.Answer:ALTER TABLE CUSTOMER ADD PRICE NUMBER (10, 2).

Question 8:What is the use of wildcardAnswer:The wildcard operators are used with the LIKE operator to search a value similar to a specific pattern in a column. There are 2 wildcard operators.% – represents 0,1 or many characters – – represents a single number or character

Question 9:Differentiate between DELETE and DROP table commands ?Answer:DELETE command is used to remove infor¬mation from a particular row or rows. If used without condition, it will delete all row information but not the structure of the table. It is a DML command.DROP table command is used to remove the entire structure of the table and information. It is a DDL command

Long Answer Type Questions

Question 1:Write SQL commands for the queries (i) to (iv) and output for (v) & (viii) based on a table COMPANY and CUSTOMER.

To display those company name which are having prize less than 30000.

To display the name of the companies in reverse alphabetical order.

To increase the prize by 1000 for those customer whose name starts with „S?

To add one more column totalprice with decimal] 10,2) to the table customer

SELECT COUNT(*) , CITY FROM COMPANY GROUP BY CITY;

SELECT MIN(PRICE), MAX(PRICE) FROM CUSTOMER WHERE QTY>10;

SELECT AVG(QTY) FROM CUSTOMER WHERE NAME LIKE “%r%;

SELECT PRODUCTNAME,CITY, PRICEFROM COMPANY, CUSTOMER WHERECOMPANY. CID=CUSTOMER.CID ANDPRODUCTNAME=”MOBILE”;

Answer:

SELECT NAME FROM COMPANY WHERE COMPANY.CID=CUSTOMER. CID ANDPRICE < 30000;

SELECT NAME FROM COMPANY ORDER BY NAME DESC;

UPDATE CUSTOMERSET PRICE = PRICE + 1000WHERE NAME LIKE ‘S%’;

ALTER TABLE CUSTOMERADD TOTALPRICE DECIMAL(10,2);

50000,70000

Question 2:Consider the following tables SCHOOL and ADMIN and answer this question :

Write SQL statements for the following:

To display TEACHERNAME, PERIODS of all teachers whose periods are more than 25.

To display all the information from the table SCHOOL in descending order of experience.

To display DESIGNATION without dupli¬cate entries from the table ADMIN.

To display TEACHERNAME, CODE and corresponding DESIGNATION from tables SCHOOL and ADMIN of Male teachers.

Answer:

SELECT TEACHERNAME, PERIODSFROM SCHOOL WHERE PERIODS>25:

SELECT * FROM SCHOOL;

SELECT DISTINCT DESIGNATION FROM ADMIN;

SELECT TEACHERNAME.CODEDESIGNATION FROMSCHOOL.CODE = ADMIN.CODEWHERE GENDER = MALE;

Question 3:Write SQL commands for the queries (i) to (iv) and output for (v) to (viii) based on the tables Watches’ and Sale given below.

TO DISPLAY ALL THE DETAILS OF THOSE WATCHES WHOSE NAME ENDS WITH ‘TIME’

TO DISPLAY WATCH’S NAME AND PRICE OF THOSE WATCHES WHICH HAVE PRICE RANGE IN BE-TWEEN 5000-15000.

TO DISPLAY TOTAL QUANTITY IN STORE OF UNISEX TYPE WATCHES.

TO DISPLAY WATCH NAME AND THEIR QUANTITY SOLD IN FIRST QUARTER;

SELECT MAX (PRICE), MIN(QTY_STORE) FROM WATCHES;

SELECT QUARTER, SUM(QTY SOLD) FROM SALE GROUP BY QUARTER;

SELECT WATCH_NAME, PRICE, TYPE FROM WATCHES W, SALE S WHERE W. WAT£H1D!=S.WATCHID; (viii) SELECT WATCH_NAME, QTYSTORE, SUM (QTY_SOLD), QTY_STORESUM (QTYSOLD) “STOCK” FROM WATCHES W, SALE S WHERE W. WATCHID = S.WATCHID GROUP BY S.WATCHID;

Answer:

SELECT * FROM WATCHES WHERE WATCH_NAME LIKE ‘%TIME’(Vi mark for SELECT query) (Vi mark for where clause)

SELECT WATCH_NAME, PRICE WATCH WHERE PRICE BETWEEN 5000 AND 15000;(Vi mark for SELECT query) (Vz mark for where clause)

SELECT SUM (QTY STORE) FROM WATCHES WHERE TYPE LIKE ‘UNISEX’;(Vz mark for SELECT query) (Vi mark for where clause)

SELECT WATCHNAME, QTY SOLD FROM WATCHES W,SALE S WHERE W. WATCHID = S. WATCHIDAND QUARTER = 1;

Question 4:Answer the questions (a) and (b) on the basis of the following tables SHOP and ACCESSORIES.

(a) Write the SQL queries:

To display Name and Price of all the Accessories in ascending order of their Price.

To display Id and SName of all Shop located in Nehru Place.

To display Minimum and Maximum Price of each Name of Accessories.

To display Name, Price of all Accessories and their respective SName where they are available.

(b) Write the output of the following SQL

SELECT DISTINCT NAME FROM ACCESSORIES WHERE PRICE> =5000;

SELECT AREA, COUNT(*) FROM SHOPPE GROUP BY AREA;

SELECT COUNT (DISTINCT AREA) FROM SHOPPE;

SELECT NAME, PRICE*0.05 DISCOUNT FROM ACCESSORIES WHERE SNO IN (‘S02‘,S03‘);

Answer:(a)

SELECT Name, Price FROM ACCESSORIES ORDER BY Price Asc;

SELECT ID SName FROM SHOP WHERE Area=”Nehru Place”;

SELECT Name, max (Price); min(Price) FROM ACCESSORIES, Group By Name;

SELECT Name,price, Sname FROMACCESSORIES, SHOP WHERE SHOEID=ACCESSORIES.ID;

(b)

Question 5:Write SQL queries for:

To display name, fee, gender, joinyear about the applicants, who have joined before 2010.

To display names of applicants, who are playing fee more than 30000.

To display names of all applicants in ascending order of their joinyear.

To display the year and the total number of applicants joined in each YEAR from the table APPLICANTS.

To display the C_ID (i.e., CourselD) and the number of applicants registered in the course from the APPLICANTS and table.

To display the applicant’s name with their respective course’s name from the tables APPLICANTS and COURSES.

Give the output of following SQL statements:

SELECT Name, Joinyear FROM APPLICANTSWHERE GENDER=’F’ and C_ID=’A02′;

SELECT MIN (Joinyear) FROMAPPLICANTSWHERE Gender=’m’;

SELECT AVG (Fee) FROM APPLICANTSWHERE C_ID=’A0T OR C_ID=’A05′;

SELECT SUM- (Fee), C_ID FROM C_ IDGROUP BY C_IDHAVING COUNT(*)=2;

Answer:

SELECT NAME,FEE,GENDER,JOINYEARFROM APPLICANTSWHERE J OINYE AR <2010

SELECT NAME FROM APPLICANTS WHERE FEE >30000

SELECT NAME FROM APPLICANTS ORDERBY JOINYEAR ASC

SELECT YEAR, COUNT]*) FROMAPPLICANTS GROUP BY YEAR;

SELECT C_ID, COUNT]*) FROMAPPLICANTS, COURSES GROUP BY IDWHERE APPLICANTS.C_ID=COURSES. C_ID

SELECT NAME,COURSE FROMAPPLICANTS, COURSESWHERE APPLICANTS. C_ID=COURSES. C_ID

Avisha 2009

2009

55000 A01

Question 6:Write SQL queries for (a) to (g) and write the output for the SQL queries mentioned shown in (hi) to (h4) parts on the basis of table ITEMS and TRADERS :

To display the details of all the items in ascending order of item names (i.e., INAME).

To display item name and price of all those items, whose price is in the range of 10000 and 22000 (both values inclusive).

To display the number of items, which are traded by each trader. The expected output of this query should be:

To display the price, item name and quantity (i.e., qty) of those items which have quantity more than 150.

To display the names of those traders, who are either from DELHI or from MUMBAI.

To display the names of the companies and the names of the items in descending order of company names.

Obtain the outputs of the following SQL queries based on the data given in tables ITEMS and TRADERS above.

SELECT MAX (PRICE), MIN (PRICE) FROM ITEMS;

SELECT PRICE*QTYFROM ITEMS WHERE CODE-1004;

SELECT DISTINCT TCODE FROM ITEMS;

SELECT INAME, TNAME FROM ITEMS I, TRADERS T WHERE I.TCODE=T.TCODE AND QTY< 100;

Answer:

SELECT INAME FROM ITEMS ORDER BYINAME ASC;

SELECT INAME, PRICE FROM ITEMS WHERE PRICE => 10000 AND PRICE =< 22000; (c) SELECT TCODE, COUNT (CODE) FROM ITEMS GROUP BY TCODE;

SELECT PRICE, INAME, QTY FROM ITEMS WHERE (QTY> 150);

SELECT TNAME FROM TRADERS WHERE (CITY = “DELHI”) OR (CITY = “MUMBAI”)

SELECT COMPANY, INAME FROM ITEMSORDER BY COMPANY DESC;

(hi) 380001200(h2)1075000(h3)T01T02TO3(h4) LED SCREEN 40 DISP HOUSE INC CAR GPS SYSTEM ELECTRONICS SALES

Question 7:Write SQL queries for (a) to (f) and write the outputs for the SQL queries mentioned shown in (gl) to (g4) parts on the basis of tables PRODUCTS and SUPPLIERS

To display the details of all the products in ascending order of product names (i.e., PNAME).

To display product name and price of all those products, whose price is in the range of 10000 and 15000 (both values inclusive).

To display the number of products, which are supplied by each suplier. i.e., the expected output should be;

S01 2

S02 2

S03 1

To display the price, product name and quantity (i.e., qty) of those products which have quantity more thhn 100.

To display the names of those suppliers, who are either from DELHI or from CHENNAI.

To display the name of the companies and the name of the products in descending order of company names.

Obtain the outputs of the following SQL queries based on the data given in tables PRODUCTS and SUPPLIERS above.

SELECT DISTINCT SUPCODE FROM PRODUCTS;

SELEC MAX (PRICE), MIN (PRICE) FROM PRODUCTS;

SELECT PRICE*QTYFROM PRODUCTS WHERE PID = 104; (g4)

SELECT PNAME, SNAMEFROM PRODUCTS P, SUPPLIERS S WHERE E SUPCODE = S. SUPCODEAND QTY>100;

Answer:

SELECT * FROM PRODUCTS ORDER BY PNAME ASC;

SELECT PNAME, PRICE FROM PRODUCTS WHERE ((PRICE => 10000) AND (PRICE = < 15000));

SELECT SUPCODE, COUNT (PID) FROM PRODUCTS GROUP BY SUPCODE;

SELECT PRICE, PNAME, QTY FROM PRODUCTS WHERE (QTY > 100);

SELECT SNAME FROM SUPPLIERS WHERE ((CITY = “DELHI”) OR (CITY = “CHENNAI”));

SELECT COMPANY, PNAME FROM PRO-DUCTS ORDER BY COMPANY DESC; 4

SOI1(gl)s02 s03(g2) 280001100(g3) 550000(g4) PNAME SNAME ViDIGITAL CAMERA 14 X GETALL INCPENDRIVE16 GB GETALL INC

Question 8:Consider the following tables CARDEN and CUSTOMER and answer (b) and (c) parts of this question:

Give a suitable example of a table with sample data and illustrate Primary and Alternate Keys in it.

Write SQL commands for the following statements:

To display the names of all the silver coloured cars.

To display names of car, make and capacity of cars in descending order of their sitting capacity.

To display the highest charges at which a vehicle can be hired from CARDEN.

To display the customer name and the corresponding name of the cars hired by them.

Give the output of the following SQL queries:

SELECT COUNT(DISTINCT Make) FROM CARDEN;

SELECT MAX(Charges), MIN (Charges) FROM CARDEN;

SELECT COUNTS), Make FROM CARDEN;

Answer:

Primary Key of CARDEN = Ccode CARDENAlternate Key = CarName:Primary key of Customer = CodeAlternate Key of Customer = Cname 2

SELECT CarName From CARDENWHERE Color = “SILVER”;

SELECT CarName, Make, Capacity FromCARDEN ORDER BY Capacity DESC;

SELECT MAX(Charges) Frm CARDEN;

ELECT Cname, CarName FromCARDEN, CUSTOMER WHERECARDEN. Ccode = CUSTOMER. Ccode;

(i) 4(ii) MAX(Charges) MIN (Charges)35 112(iii) 5(iv) SX4C Class

Question 9:Consider the following tables CABHUB and CUSTOMER and answer (b) and (c) parts of this question :

Give a suitable example of a table with sample data and illustrate Primary and Candidate Keys in it.

Write SQL commands for the following statements:

To display the names of all the white coloured vehicles.

To display name of vehicle name and capacity of vehicles in ascending order of their sitting capacity.

To display the highest charges at which a vehicle can be hired from CABHUB.

To display the customer name and the corresponding name of the vehicle hired by them.

Give the output of the following SQL queries :

SELECT COUNT(DISTINCT Make) FROM CABHUB;

SELECT MAX(Charges), MIN(Charges)

FROM CABHUB;

SELECT COUNT (*) Make FROM CABHUB;

SELECT Vehicle FROM CABHUB WHERE Capacity=4;

Answer:

Primary key of CABHUB = Vcode alternate key of CABHUB = Vehicle Name. Primary key of Customer = Ccode Alternate Key of CUSTOMER = Cname.

(i) SELECT VehicleName FROM CABHUBWHERE Colour = “WHITE”;

SELECT VehicleName, capacity From CABHUB ORDER BY Capacity ASC;

SELECT MAX(Charges) FROM CABHUB;

SELECT Cname,VehicleName FROM CABHUB, CUSTOMER WHERE CUSTOMER. Vcode=CABHUB. Vcode;

(i) 4(ii) MAX(Charges) MIN (Charges)35 12(iii) 5(iv) SX4C Class

Question 10:Consider the following tables EMPLOYEE and DEPARTMENT and answer (a) and (b) parts of this question.

Write SQL commands for the following statements:

To display all DepName along with the DepCde in descending order of DepCde.

To display the average age of Employees in DepCde as 103.

To display the name of DepHead of the Employee named “Sanjeev P”

To display the details of all employees who has joined before 2007 from EMPLOYEE table.

Give the output of the following SQL queries:

SELECT COUNT (DISTINCT DepCde) FROM EMPLOYEE;

SELECT MAX(JoinDate), MIN (JointDate) FROM EMPLOYEE;

SELECT TName, DepHead FROM EMPLOYEE E, DEPARTMENT DWHERE E.DepCde = D.DepCde;

SELECT COUNT (*) FROM EMPLOYEE WHERE Salary > 60000 AND Age > 30;

Answer:

(a)

SELECT DEPNAME, DEPARTME-NT.DepCde FROM EMPLOYEE, DEPARTMENT WHERE EMPLOYEE. DepCDE=DEPARTMENT. DepCde Order by DepCde DESC;

Select AVG (Age) from EMPLOYEE WHERE DepCde=”103″;

SELECT DeptHead FROM DEPARTMENT WHERE Employee. TName=“Sanjeev P” AND EMPLOYEE. DepCde= DEPARTMENT. DepCde;

SELECT * from EMPLOYEE WHEREjoinDate<’01-JAN-2007′;

Question 11:Consider the following tables WORKER and PAYLEVEL and answer (a) and (b) parts of this question:

(a) Write SQL commands for the following statements:

To display the name of all Workers in descending order of DOB.

To display NAME and DESIGN of those Workers, whose PLEVEL is either P001 or

To display the content of all the workers table, whose DOB is in between ’19-JAN- 1984′ and ’18-JAN-1987′.

To add a new row with the following:19, ‘DayaKishore’, ‘Operator’, ‘P003′, ’19- Sep-2008’, ‘ll-Jul-1984’

(b) Give the output of the following SQL queries :

SELECT COUNT (PLEVEL), PLEVEL FROM WORKER GROUP BY PLEVEL;

SELECT MAX(DOB), MIN(DOJ) FROM WORKER;

SELECT Name,PAY FROM WORKERW,PAYLEVEL P WHERE W.LEVEL=P.PLEVEL AND W.ECODE<13;

SELECT PLEVEL, PAYLEVELWHERE PLEVEL=”POO3″;

Answer:

(a)

SELECT NAME FROM WORKERORDER BY DOBDESC;

SELECT NAME, DESIGN FROM WORKER WHERE PLEVEL=”POOO1″ ORPLEVEL=”POO2″;

SELECT * FROM WORKER WHEREDOB BETWEEN ’19-JAN-1984 AND ’18-JAN-1987′;

INSERT INTO WORKER VALUES (19,”DayaKISHORE”, “oPERATOR”, “P0003”,’19-Sep-2008′,’11-Jul-1984′)’

(b)

Question 12:Consider the following tables EMPLOYEE and SALGRADE and answer (b) and (c) parts of this question:

(a) What do you understand by Selection and Projection operations in relational algebra ?(b) Write SQL commands for the following statements :

To display the details of all EMPLOYEES in descending order of DOJ.

To display NAME and DESIGN of those EMPLOYEES, whose SAL-GRADE is either S02 or S03.

TO display the content Of all the EMPLOYEES table, whose DOJ is in between ’09-Feb-2006′ and ’08-Aug-2009′.

To add a new row with the following:109, ‘HarishRoy’, ‘HEAD-IT’, ‘SOX, ’09-Sep-2007′, ’21-Apr-1983’

SELECT COUNT(SGRADE), SGRADEFROM EMPLOYEE GROUP BYSGRADE;

SELECT MIN(DOB), MAX(DOJ) FROM EMPLOYEE;

SELECT NAME, SALARY FROMEMPLOYEE E, SAL-GRADE S WHEREE.SGRADE= S.SGRADE AND E.ECODE<103′;

SELECT SGRADE, SALARY +HRA FROM SALGRADE WHERE SGRADE =SGRADE=’S02;’

Answer:Projection(ff): In relational algebra, a projection is a unary operafion. The result of such projecion is defined as the set obtained when the components Of the tuple R are restriceted to the set {a1……an}. It discards (or excludes) the other attributes.Selection(): In relational algebra, a selectionis a unary operation written as (R) or (R) where:

a and b are attribute names.

p is a binary operation in the set.

v is a value constant.

R is a relation.

The selection (R) selects all those tuples in R for which 9 holds between the a and the b

(b)

SELECT FROM EMPLOYEE ORDER BY DOJ DESC;

SELECT NAME, DESIGN FROM EMPLOYEE WHERE SGRADE – “S02” OR SGRADE = “SO3;

SELECT * FROM EMPLOYEE WHERE DOJ BETWEEN ’09-FEB-2006′ AND ’08- AUG -200%

INSERT INTO EMPLOYEE VALUES(109, “HARSH RAY”, “HEAD-IT.S02”, ’09-SEP-2007′, ’21-APR-1983′);

Question 13:Consider the following tables GAMES and PLAYER and answer (b) and (c) parts of this question :

(a)What do you understand by primary key and candidate keys ?(b)Write SQL commands for the following statements:

To display the name of all GAMES with their GCodes.

To display details of those GAMES which are having PrizeMoney more than 7000.

To display the content of the GAMES table in ascending order of Schedule Date.

To display sum of PrizeMoney for each type of GAMES.

SELECT COUNT(DISTINCT Number) FROM GAMES;

SELECT MAX(ScheduleDate), MIN(Sche- duleDate) FROM GAMES

SELECT Name, GameName FROM GAMES G, PLAYER PWHERE (G.Gcode=PGcode AND G.Pri- zeMoney>10000);

SELECT DISTINCT Geode FROM PLAYER;

Answer:

(a) An attribute or set of attributes which are used to identify a tuple uniquely is known as a primary key. If a table has more than one such attributes which identify a tuple uniquely than all such attributes are known as candidate keys.

(b)

SELECT GameName, GCode FROM GAMES;

SELECT * FROM Games WHERE PrizeMoney >7000;

SELECT * FROM Games ORDER BY ScheduleDate;

SELECT SUM(Pnzemoney) FROM Games GROUPBY Type;

(c)

19-Mar-2004 12-Dec-2003

Ravi Sahai Lawn Tennis

101 108 103

Question 14:Consider the following tables ACTIVITY and COACH and answer (a) and (b) parts of this question :

(a) Write SQL commands for the following statements:

To display the names of all activities with their Acodes in descending order.

To display sum of PrizeMoney for the Activities played in each of the Stadium separately.

To display the coach’s name and acodes in ascending order of Acode from the table Coach.

To display the content of the Activity table whose schedule date earlier than 01-01-2004 in ascending order of Participants Num.

(b) Give the output of the following SQL queries:

SELECT COUNT (DISTINCT Participants Num) FROM ACTIVITY;

SELECT MAX (Schedule Date), Min (Schedule Date) FROM ACTIVITY;

SELECT Name, Activity Name FROM ACTIVITY A, COACH CWHERE A.Acode=C.Acode AND A.Parti- cipants Num=10;

SELECT DISTINCT Acode FROM COACH;

Answer:

(a)

SELECT Acodes, ActivityName FROM ACTIVITY ORDER BY ACode DESC;

SELECT SUM(PrizeMoney) FROM ACTIVITY GROUP BY Stadium;

SELECT Name, Acode FROM COACH ORDER BY Acode;

SELECT * FROM ACTIVITY WHERE SchduleDate < ’01-Jan-2004′ ORDER BY ParticipantsNum;

(b)

12-Dec-2003 19-Mar-2004

Ravinder Discuss Throw

100110081003

Question 15:Consider the following tables RESORT and OWNEDBY and answer (a) and (b) parts of this question:

(a)Write SQL commands for the following statements:

To display the RCODE and PLACE of all ‘5 STAR’ resorts in the alphabetical order of the place from table RESORT.

To display the maximum and minimum rent for each type of resort from table RESORT.

To display the details of all resorts which are started after 31-DEC-05 from table RESORT.

Display the OWNER of all ‘5 STAR’ resorts from tables RESORT and OWNEDBY.

(b)Give output for the following SQL queries:

SELECT MIN(RENT) FROM RESORT Where PLACE = ‘KERALA’;

SELECT TYPE, START DATE FROM RESORT Where TYPE ‘2 STAR’ORDERBY STARTDATE,

SELECT PLACE, OWNER FROMOWNEDBY Where PLACE LIKE “%A”;

SELECT RCODE, RENT FROM RESORT, OWNEDBY WHERE (RESORT PLACE= OWNEDBY. PLACE AND TYPE = ‘3 STAR’);

Answer: (a)

SELECT RCODE, PLACE FROM RESORT mere TYPE = “5 STAR” ORDERBY PLACE;

SELECr MAX (RENT), MIN (RENT) FROM RESORT GROUP BY TYPE;

SELECT FROM RESORT WHERE OSWAAL (BSE Question Bank. COMPUTER SCIENCE – PYTHON, STARTDATE > ’31-DEC-05′;

SELECT OWNER FROM RESOR OWNEDBY B WHERE (A.TYPE START’ AND A.PLACE B.PLACE);

(b)

Question 16:Consider the following tables STORE and SUPPLIERS and answer (a) and (b) parts of this question:

(a) Write SQL commands for the following statements:

To display details of all the items in the STORE table in ascending order of LastBuy.

To display ItemNo and Item name of those items from STORE table whose Rate is more than 15 Rupees.

To display the details of those items whose supplier code (Scode) is 22 or Quantity in Store (Qty) is more than 110 from the table Store.

To display minimum Rate of items for each supplier individually as per Scode from the table STORE.

(b) Give the output of the following SQL queries:

SELECT COUNT(DISTINCT Scode) FROM STORE;

SELECT Rate* Qty FROM STORE WHERE ItemNo=2004;

SELECT Item, Sname FROM STORE S, Suppliers P

WHERE S.Scode=PScode AND ItemNo=2006;

SELECT MAX(LastBuy) FROM STORE;

Answer:

(a)

SELECT * FROM STORE ORDER BY LastBuy ASC;

SELECT ItemNo, Item FROM STORE WHERE Rate > 15;

SELECT * FROM STORE WHERE (Scode = ’22’ OR Qty >’110′);

SELECT Sname, MIN(Rate) FROM STORE, SUPPLIERS WHERE STORE. Scode = SUPPLIERS.Scode GROUP BY Sname;

(b)

880

Item SnameGel Pen Classic Premium Stationers

24-Feb-10

Question 17:Consider the following tables STOCK and DEALERS and answer (a) and (b) parts of this question:

(a)Write SQL commands for the following statements:

To display the details of all Items in the STOCK table in ascending order of StockDate.

To display ItemNo and Item name of those items from STOCK table whose UnitPrice is more than Rupees 10.

To display the details of those items whose dealer code (Dcode) is 102 or quantity in STOCK (Qty) is more than 100 from the table Stock.

To display maximum UnitPrice of items for each dealer individually as per Dcode from the table STOCK.

(b)Give the output of the following SQL queries:

SELECT COUNT(DISTINCT Dcode)FROM STOCK;

SELECT Qty* UnitPrice FROM STOCK WHERE ItemNo=5006;

SELECT Item, Dname FROM STOCK S, Dealers D WHERE S.Dcode=D.Dcode AND ItemNo = 5004;

SELECT MIN (StockDate) FROM STOCK;

Answer:

(a)

SELECT*FROM STOCK ORDER BY StockDate;

SELECT Item No, Item FROM STOCK WHERE UnitPrice >10;

SELECT *FROM DEALERS, STOCKWHERE (DEALERS.Dcode=”102″OR STOCK.Qty >100 and DEALERS. DCODE = STOCK.DCODE);

SELECT MAX (Unitprice) FROM DEALERS, STOCK ORDER BY STOCK. Dcode WHERE DEALERS.Dcode = STOCK.Dcode;

(b)

4400

Item DnameEraser Big Clear Deals

01-Jan-09

via Blogger https://ift.tt/35CUZXv

#Blogger

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NCERT Class 12 Computer Science Chapter 3 Lists Manipulation and Implementation

NCERT Class 12 Computer Science Python Solutions for Chapter 3 :: Lists Manipulation and Implementation

TOPIC-1

Data StructuresShort Answer Type Questions (2 marks)

Question 1:Define a data structure.Answer:A data structure is a group of data which can be processed as a single unit. This group of data may be of similar or dissimilar data types. Data Structures are very useful while programming because they allow processing of the entire group of data as a single unit.

Question 2:Name the two types of data structures and give difference between them.Answer:Data structures are of two types: Linear and Non – Linear.

In a linear data structure, the elements are stored in a sequential order.

In a non linear data structure, no sequential order is followed.

Linear Data Structure Examples: Arrays: Non-Linear Data Structure Examples: Tree, graph lists, stacks, queues, linked lists.

Question 3:Give difference between an array and a list in Python.Answer:An array is defined as a set of contiguous data of similar data type. Python lists are actually arrays of variable length. The elements of a list are of eterogeneous types which means they are of different data types.

Question 4:How are lists implemented in memory?(or)How is memory allocated to a list in Python?Answer:A list in Python is an array that contains elements (pointers to objects) of a specific size only and this is a common feature of all dynamically typed languages. For implementation of a list, a contiguous array of references to other objects is used. Python keeps a pointer to this array and the array’s length is stored in a list head structure. This makes indexing of a list independent of the size of the list or the value of the index. When items are appended or inserted, the array of references is resized.

Question 5:What is sequential allocation of memory? Why do we say that lists are stored sequentially?Answer:A list is a allocated memory in sequential manner. This means that the elements of the list are stored in memory in sequence of their declaration. So, if you want to view the fifth element of the list, you have to first traverse through first four elements of the list. This is called sequential allocation of memory.

TOPIC-2Searching ListsShort Answer Type Questions-I (2 marks)

Question 1:How is linear search different from binary search?Answer:

Binary search requires the input data to be sorted near search doesn’t.

Binary search requires an ordering comparison; linear search only requires equality comparisons

Binary search has complexity 0(log n); linear search has complexity O(n) as discussed earlier.

Binary search requires random access to the data; linear search only requires sequential access (this can be very important – it means a linear search can stream data of arbitrary size).

Short Answer Type Questions-II (2 marks)

Question 1:Accept a list containing integers randomly. Accept any number and display the position at which the number is found in the list.Answer:maxrange = input(“Enter Count of numbers: ’’)marks=[]flag=Falsefor i in range(0, maxrange):marks. append(input(“ ?”))number = inputfEnter number to be searched”)for i in range(0, maxrange):if marks [i]==number:print number,“found at position”,iflag=Trueif flag==False:print number, “not found in list”

Question 2:What will be the status of the following list after the First, Second and Third pass of the slection sort method used for arranging the following elements in descending order?Note : Show the status of all the elements after each pass very clearly underlining the changes.12,14, -54,64,90,24Answer:

Question 3:For a given list of values in descending order, write a method in Python to search for a value with the help of Binary search method. The method should return position of the value and should return -1 if the value not present in the list.Answer:def binarysrch (nums, x):high=len (nums)low=0while low < high:mid=(low+high)/2midval=nums [mid]if midval > x:low = mid + 1elif midval < x:high = midelse:return midreturn -1

TOPIC-3List SortingShort Answer Type Questions-I (2 marks)

Question 1:What is bubble sort?Answer:Bubble sort is a simple sorting algorithm that works by repeatedly stepping through the list to be sorted, comparing each pair of adjacent items and swapping them if they are in the wrong order. The pass through the list is repeated until no swaps are needed, which indicates that the list is sorted. The algorithm gets its name from the way smaller elements “bubble” to the top of the list. Because it only uses comparisons to operate on elements, it is also Called a comparison sort.

Question 2:Write an algorithm for selection sort.Answer:Selection sort performs the following steps:

Starting at index 0, search the entire array to find the next smallest or largest value.

Swap the smallest or largest value found with the value at index 0.

Repeat steps 1 & 2 starting from the next index.

Question 3:Explain insertion sort.Answer:Every repetition of insertion sort removes an element from the input data, inserting it into the correct position in the already-sorted list, until no input elements remain. The choice of which element to remove from the input is arbitrary and can be made using almost any choice algorithm.

Short Answer Type Questions-II (2 marks)

Question 1:Write a function that takes a list that is sorted in ascending order and a number as argument. The function should do the following:

Insert the number passed as argument in a sorted list.

Delete the number from the list.

Answer:from bisect import bisectdef listfunc(sortedlist,number) :insert_point = bisect (sortedlist, number)sortedlist.insert(insert_point,number)print “List after Insertion”print sortedlistsortedlist.remove(number)print “List after Deletion”print sortedlistmaxrange = inputfEnter Count of numbers: ”)numlist=[]flag=Falsefor i in range(0, maxrange):numlist.append(input(“ ?”))numlist.sort()number = inputfEnter the number”)listfunc(numlist,number)

Question 2:Consider the following list 95 79 19 43 52 3Write the passes of bubble sort sorting the list in ascending order till the 3rd iteration.Answer:[79,19, 43, 52, 3, 95]-Pass 1[19, 43,52,3,79, 95]-Pass 2[19,43,3, 52, 79, 95]-Pass 3

Question 3:Write a function that takes a sorted list and a number as an argument. Search for the number in the sorted list using binary search.Answer:def binary_search(SORTEDLIST, number):low=0high=len(SORTEDLIST)found=Falsewhile(low<high) and found==False:mid=(int) (low+high/2)if SORTEDLIST[mid]==number:print “Number found at”,midfound=Truebreakelif SORTEDLIST[mid]<number:low=mid+1else:high=mid-1if low >= high:print “Number not found”maxrange = inputfEnter Count of numbers: ”)numlist = []for i in range(0, maxrange):numlist.append(input(“?”))numlist.sort()print “Sorted list”,numlistnumber = inputfEnter the number”)binary_search(numlist,number)

Question 4:In the following list containing integers, sort the list using Insertion sort algorithm. Also show the status of the list after each iteration.15 -5 20 -10 10Answer:def insertion_sort(DATA_LIST):for K in range (1, len(DATA_LIST)):temp=DATA_LIST[K] # ptr=K-1,while(ptr>=0) and DATA_LIST[ptr]>temp:DATA_LIST[ptr+l]=DATA_LIST[ptr]ptr=ptr-1DATA_LIST [ptr+1] =tempprint DATA_LISTDATA_LIST = [15,-5,20,-10,10]print “LIST BEFOR SORTING”,DATAJ.ISTinsertion_sort(DATA_LIST)[-5,15, 20, -10,10][-5,15,20,-10,10]-Pass 1[-10,-5,15,20,10]-Pass 2[-10,-5,10,15, 20]-Pass 3

Question 5:What will be the status of the following after the First, Second and Third pass of the insertion sort method used for arranging the following elements in descending order ?Note: Show the status of all the elements after each pass very clearly underlining the changes.Answer:

Question 6:Consider the following unsorted list:99 78 25 48 51 11Sort the list using selection sort algorithm. Show the status of the list after every iteration.Answer:def selection_sort(DATA_LIST):for i in range(0, len (DATA_LIST)):min = ifor j in range(i + 1, len(DATA_LIST)):if DATA_LIST[j] < DATA_LIST[min]:min = j# swappingtemp= DATA_LIST[min]DATA_LIST[min] = DATA_LIST[i]DATA_LIST [i]=tempprint DATA_LISTDATA_LIST = [99 78 25 48 51 11]print “LIST BEFOR SORTING”,DATA_LISTselection_sort(DATA_LIST)

Question 7:Consider the following unsorted list Neena Meeta Geeta Reeta Seeta Sort the list using selection sort algorithm. Show the status of the list after every iteration.(or)Sort a list containing names of students in ascending order using selection sort.Answer:def selection_sort(DATA_LIST):for i in range(0, len (DATA_LIST)):min = ifor j in range(i + 1, len(DATA_LIST)):if DATA_LIST[j] < DATA_LIST[min]:min = j# swappingtemp= DATA_LIST[min]DATA_LIST[min] = DATA_LIST[i]DATA_LIST[i]=tempprint DATA_LISTNAME_LIST = [‘Neena’,’Beeta’,’Reeta’,’Geeta’,’Seeta’]print “LIST BEFORE SORTING”,NAME_LISTselection_sort(NAME_LIST)LIST BEFORE SORTING [‘Neena’,‘Beeta’,‘Reeta’, ‘Geeta’, ‘Seeta’][‘Beeta’, ‘Neena’, ‘Reeta’, ‘Geeta’, ‘Seeta’]-Pass 1[‘Beeta’, ‘Geeta’, ‘Reeta’, ‘Neena’, ‘Seeta’]-Pass 2[‘Beeta’, ‘Geeta’, ‘Neena’, ‘Reeta’, ‘Seeta’]-Pass 3[‘Beeta’, ‘Geeta’, ‘Neena’, ‘Reeta’, ‘Seeta’]-Pass 4[‘Beeta’, ‘Geeta’, ‘Neena’, ‘Reeta’, ‘Seeta’]-Pass 5

Question 8:A list contains rollno, name and marks of the student. Sort the list in descending order of marks using selection sort algorithm. [CBSE Text Book]Answer:def selection_sort(DATA_LIST):for i in range(0, len (DATA_LIST)):min = ifor j in range(i + 1, len(DATA_LIST)):if DATA_LIST[j][2] > DATA_LIST[min][2]:min = j# swappingDATA_LIST[min] [0] ,DATA_LIST[i] [0] = DATA_LIST[i] [0] ,DATA_LIST[mm] [0] DATA_LIST[min][l],DATA_LIST[i][l] = DATA_LI ST [i] [ 1 ],DATA_LI ST [min] [ 1 ] DATA_LIST[min] [2] ,DATA_LIST[i] [2] = DATA_LIST[i] [2],DATA_LIST[min] [2]print DATA_LISTmaxrange=input(“Enter Number of Students: ”)Students=[]for i in range(maxrange):Details=[]Details. append(input(“Enter roll_no”))Details.append(raw_input(“Enter name”))Details. append(inprft(“Enter marks”))Students.append(Details)print Studentsselection_sort(Students)

Question 9:What will be the status of the following list after the First. Second and Third pass of the insertion sort method used for arranging the following elements in descending order ?12,34,46, -34,90,23Note : Show the status of all the elements after each pass very clearly underlining the changes.Answer:output of diferent passes Pass One[12,34,46,-34,90,23], {}Pass Two[34, 46, -34, 90, 23} , {12}Pass ThreeLISTS MANIPULATION AND IMPLEMENTATION[46, -34, 90, 23} , {12, 34} Pass SixPass Four {23}, {-34,12, 34, 46, 90}[-34, 90, 23} , { 12, 34, 46} Pass SevenPass Five {} , {-34,12, 23, 34, 46, 90}{90,23} , {-34,12,34,46} It is the sorted list.

Long Answer Type Questions (4 marks)

Question 1:Consider the following unsorted list: 90 78 20 46 54 1 Write the list after:

3rd iteration of selection sort

4th iteration of bubble sort

5th iteration of insertion sort Ans. Working :

Answer:Working :

3rd iteration of selection sort: [1,20,46,78,54,90]

4th iteration of bubble sort: [1, 20, 46, 54, 90, 78]

5th iteration of insertion sort: [1, 20, 46, 54, 78, 90

Question 2:Consider the following unsorted list:10 5 55 13 3 49 36Write the position of elements in the list after:(i) 5th iteration of bubble sort(ü) 7th iteration of insertion sort(iii) 4th iteration of selection sortAnswer:Working :

5th iteration of bubble sort: [3, 5,10,13, 36, 55, 49]

Insertion sort doesn’t have the 7th iteration

4th iteration of selection sort: [3, 5,10,13, 55, 49, 36]

Question 3:Write a class CITY in Python with following– CName # String Value specifications :– Pop # Numeric value for Population instance attributes-KM # Numeric value– Ccode # Numeric value– Density #Numeric value for Population DensityMethods:– Dencal() #Method to calculate Density as Pop/KM– Record() #Method to allow user to enter values Ccode, CName, Pop, KM and call DenCal ( ) method– View() #Method to display all the members also display a message “Highly Populated City” if the Density is more than 10000.Answer:class CITY:def_init_(self): self.Ccode = 0self.CName = self. Pop = 0self.KM = 0 self.Density = 0def DenCal (self) :self.Density = self.Pop/self. KMdef Record (self)self Ccode=input (“Enter Ccode”)self.CName=raw_input (“Enter CName”)self.Pop=input (“Enter population”)self.KM=input (“Enter KM”)DenCal(self) //or self.DenCal()def View (self):print Ccode, CName, Pop, KM, Densityif self.Density > 10000:print (“Highly populated city”)# OR print (“Highly populated city”)

Question 4:A list contains Item_code, Item_name, qty and price. Sort the list :

In ascending order of qty using Bubble sort.

In descending order of price using Insertion sort.

Answer:def bubble_sort(DATA_LIST) :i = 0j = 0l = len(DATA_LIST)for i in range(l):print “Bubble Sort Iterations – Asc order of Quantity”for j in range(i+l,l):if DATA_LlST[i][3] > DATA_LIST[j][3]:# swappingDATA_LIST[i][0], DATA_LIST[j] [0]=DATA LIST[j] [0],DATA_LIST[i] [0]DATA_LIST[i][1], DATA_LIST[j][1]=DATA_ LIST[j][l],DATA_LIST[i][l]DATA_LIST[i] [2], DATA_LIST[j] [2]=DATA_ LIST[j][2],DATA_LIST[i][2]DATA_LIST[i][3], DATA_LIST[j][3]=DATA_ LIST[j][3] ,DATA_LIST[i] [3]print DATA_LISTdef insertion_sort(DATA_LIST):for K in range (1, len(DATA_LIST)):temp=DATA_LIST[K][2]ptr=K-1print “Insertion Sort Iterations – Desc order of price”while(ptr>=0) and DATA_LIST[ptr][2] < temp:DATA_LIST[ptr+1] [0]=DATA_LIST[ptr] [0]DATAJHST [ptr+1] [1]=DATA_LIST[ptr] [1]DATA_LIST[ptr+1][2]=DATA_LIST[ptr][2]DATA_LIST[ptr+1] [3]=DATA_LIST[ptr] [3]ptr=ptr-1DATA_LIST[ptr+1][2]=tempprint DATA_LISTmaxrange = input(“Enter Number of Items: “)Items=[]for i in range (maxrange):Details=[]Details. append(input(“Enter Item Code”))Details.append(raw_input(“Enter Item name”))Details.append(float(raw_input(“Enter price”)))Details.append(input(“Enter Quantity”)) Items. append(Details)print “BEFORE SORTING”,Items bubble_sort(Items)insertion_sort(Items)

TOPIC-4Stacks And Queues With ListsVery Short Answer Type Questions (1 mark)

Question 1:Expand the following:

LIFO

FIFO

Answer:

LIFO: Last-In First-Out

FIFO: First-In First-Out

Question 2:Define stack.Answer:A stack is a data structure that allows adding and removing elements in a particular order. Every time an element is added, it goes on the top of the stack; the only element that can be removed is the element that was at the top of the stack.

Question 3:Define Queue.Answer:Queue is a first-in, first-out (FIFO) data structure, i.e. the element added first to the queue will be the one to be removed first. Elements are always added to the rear of the queue and removed from the front of the queue.

Question 4:Write all the operations possible in data structure.Answer:The major operations are:

Traversal

Insertion

Deletion

Searching

Question 5:What are the two major queue operations?Answer:Addition of element is known as INSERT operation, also known as enqueuing. It is done using rear terminal position, i.e. tail end. Removal of element is known as DELETE operation, also known as dequeueing.

Short Answer Type Questions-I (2 marks)

Question 1:Write an algorithm to implement push operation.Answer:

Start

Initialize top with -1.

Input the new element.

Increment top by one.

stack[top]=new element

Print “Item Inserted”

Stop

Question 2:Write an algorithm to implement pop operation.Answer:

Start

If the value of top is -1 go to step 3 else go to step 4

Print “Stack Empty” and go to step 7

Deleted item = Stack[top]

Decrement top by 1

print “Item Deleted”

Stop

Question 3:Write an algorithm to implement insertion opera¬tion of queue.Answer:

Start

Check FRONT and REAR value,

if both the values are -1, then FRONT and REAR are incremented by 1

other wise Rear is incremented by one.

queue [Rear]=new element.

Stop

Question 4:Write an algorithm to implement deletion operation of queue.Answer:

Start

Check for underflow situation by checking value of Front=-1

If it is display appropriate message and stop

Otherwise Deleted item=queue [Front]

If Front=Rear then Front=Rear=-1 Otherwise Front is incremented by one

Print “Item Deleted”

Stop

Question 5:For a given list of values in ascending order, write a method in Python to search for a value with the help of Binary Search method. The method should return position of the value and should return -1 if the value not present in the list.Answer:def Binary Search (list, search):lower_bound=0upper_bond=len(list) -1found=falsepos=’x’while lower_bound< =upper_bond:middle_pos=(lower_bound + upper_bond)/2if list [middle_pos] = = search:pos=middlepos found=True breakelif search < list [middle_pos]:upper_bound=middle_pos-l else:lower_bound=middle_pos + 1 if found:print(“The item found”, pos) else:print (“The item not available”)return (-1)

Long Answer Type Questions (4 marks)

Question 1:Write Insert (city) and Delete (City) methods in Python to add City and Romave City considering them to act as Insert and Delete operations of the data structure Queue.Answer:class queue:city=[ ]def Insert (self):a = raw_input(“Enter city”)queue.city append (a)def Delete (self):if (queue, city = = []):print “Queue empty”else:print “Deleted element is”,queue.city[0]queue.city.delete ()ORclass queue:city=[ ]def Insert(self):a=raw_input(“Enter city”)queue.a.append(a)def Delete(self):if (queue.city==[ ]):print (“Queue emtpy”)elseprint (“Deleted element is”,queue, city [0])

Question 2:Define stack class in Python to operate on stack of numbers.Answer: class Stack:def_init_(self):self.s = [ ]def push(self):a = input(“Enter number”)self.s. append(a)def pop(self):self.s.pop()def display (self):l = len(self.s)for I in range(l-1,1,-1):print self.s[i]

Question 3:Write a function to push any student’s information to stack.Answer:def push(stack):s=[]print “STACK BEFORE PUSH” display(stack)s.append(input(“Enter student rollno?”))s.append(raw_input(“Enter student name”))s.append(raw_input(“Enter student grade”))stack, append(s)def display (stack):l=len(stack)print “STACK CONTENTS”for i in range(l-1,-1,-1):print stack[i]stack=[]print “Creating Stack”n = input(“Enter the number of students”)for i in range(n): student = []student.append(input(“Enter student rollno?”))student.append(raw_input(“Enter student name”))student.append(raw_input(“Enter student grade”))stack, append(student) push(stack)display(stack)

Question 4:Write the push operation of stack containing names using class.Answer:class stack:s=[]def push(self):a=r’aw_input(“Enter any name :”)stack.s.append(a)def display(self):l=len(stack.s) for i in range(l-1,-1,-1):print stack.s[i]a=stackOn= input(“Enter no. of names”)for i in range (n):a.push()a.display()

Question 5:Write Insert (Place) and Delete (Place) methods in Python to be add Place and Remove Place considering them to act as Insert and Delete operations of the data structure Queue.Answer:Class queue: place=[]def Insert (self):a=raw_input (“Enter city”)queue.place. append (a)def delete (self):if (queue.place = = []):print “Queue empty”else:print “Deleted element is”, queue, place [0]class queue :place = [ ]def Insert (self) 1a = rawjnput (“Enter place”) queue, a.append (a)def delete (self):if (queue.place==[ ] ):print (“Queue empty”)else:print (“Deleted element is” queue, place [0])queue.place.delete ( )

Question 6:Write the pop operation of stack containing names using class.Answer:class stack:s=[]def push (self):a=raw_input(“Enter any name :”)stack.s.append(a)def pop(self):if (a.s==D):print “Stack Empty”else:print “Deleted element is : ”,a.s.pop()def display (self):l=len(stack.s)print “STACK CONTENTS”for i in range(l-1,-1,-1):print stack.s[i]a=stack()n= input(“Enter no. of names”)for i in range(n):a.push()a.pop()a.display()

Question 7:Write the pop operation of stack containing num-bers using class.Answer:class stack:s=[]def push(self):a=input(“Enter number :”)stack.s.append(a)def pop(self):if (a.s==[]):print “Stack Empty”else:print “Deleted element is : ”,a.s.pop()def display(self):l=len(stack.s) print “STACK CONTENTS”for i in range(l-1,-1,-1):print stack.s[i]a=stack()n= input(“Enter count of numbers”)for i in range (n):a.push()a.pop()a. display ()

Question 8:Write a function to add any customer’s information to queue.Answer:def insert(queue): customer=[]print “QUEUE BEFORE INSERT” display(queue)customer.append(input(“Enter customer number?’’))customer.append(raw_input(“Enter customer name”))customer.append(input(“Enter customer phone number”))queue. append(customer)def display (queue):l=len(queue)fori in range(O.l): print queue[i]queue=[]print “Creating Queue”n=input(“Enter the number of customers”)for i in range(n):customer=[]customer. append(input(“Enter customer number?”))customer.append(rawjnput(“Enter customer name”))customer.append(input(“Enter customer phone number”))queue.append(customer)insert(queue)display(queue)

Question 9:Write the insertion operation of queue containing character using class.Answer:class queue:s=0def insert(self):a=raw_input(“Enter any letter:”)queue.s.append(a)def display (self):l=len(queue.s)print “QUEUE CONTENTS”for i in range(o,l):print queue. s[i]a=queue()n= input(“Enter no. of letters”)for i in range(n): a.insert()ch = raw_input(“Do you want to insert more letters”)if ch==‘y’:a.insert()a.display()

Question 10:Write Add(Fruit) and Remove (Fruit) methods in Python to insert name of a Fruit and to delete name of a Fruit considering them to act as Insert and Delete operations of the data structure Queue.Answer:def que insert (fruit, Rear) :ch=‘y’while ch==‘y’ or ch==‘yes’Frt=input(“Enter a fruit”)Rear=Rear + 1Fruit, append (Frt)print(“Do you wand to Add more”)ch=input ().upper ( )if ch==’N’ or ch==‘No’ :breakreturn reardef quedelete (Fruit, Rear):if not len (fruist):print f(“Fruit + list is empty”)else :Rear = Rear – 1Frt = Fruit.pop( )print(“Fruit is delete from list”)return Rear

Question 11:Write the deletion operation of queue containing characters using class.Answer:class queue:s=0def insert(self):a=raw_input(“Enter any letter:”)queue.s.append(a)def delete(self):if (a.s==[]):print “Queue Empty”else:print “Deleted element is: ”,queue.s[0]del queue.s[0]def display(self): l=len(queue.s)print “QUEUE CONTENTS”for i in range(0,l):print queue.s[i]a=queue()n= input(“Enter no. of letters”)for i in range (n):a.insert()a. delete()a. display ()

Question 12:Write the deletion operation of queue containing numbers using class.Answer:class queue:s=[]def insert(self):a=input(“Enter the number:”)queue.s.append(a)def delete(self):if (a.s==Q):print “Queue Empty”else:print “Deleted element is: ”,queue.s[0]del queue.s[0]def display(self):l=len(queue.s)print “QUEUE CONTENTS”for i in range(0,l):print queue.s[i]a=queue()n= input(“Enter no. of numbers”)for i in range(n):a.insert()a.delete()a.display()

TOPIC-5Applications of StacksVery Short Answer Type Questions (1 mark)

Question 1:Give one example of infix expression.Answer:A + B *C / D

Question 2:Give one example of postfix expression.Answer:ABC*D/+

Question 3:Give one example of prefix expression.Answer:+/*BCDA

Question 4:Convert (A+B)*C in to postfix form.Answer:AB+C*

Short Answer Type Questions-I (2 marks)

Question 1:Evaluate the following postfix notation of expressio,Show status of stack after every operation.12,2,7,34,20,-, +,5, +Answer:

Question 2:Evaluate the following postfix expression. Show the status of stack after execution of each operation separately: 2,13, + , 5, -,6,3,/,5,*,<Answer:Stack contentsResult: 0

Question 3:Evaluate using stack 10, 3,*, 30, 2,*,-Answer:

Question 4:Evaluate the following Postfix expression :20,10,-15,3,/, +, 5, *Answer:

Question 5:Convert A+ (B*C – (D / E A F) * G) * H into postfix form showing stack status after every step.Answer:

Question 6:Convert (True And False) OR (False And True) into postfix form using stack.Answer:

Question 7:What are the applications of queue in computer?Answer:In a single processor multitasking computer, job(s) wait to be processed form a queue. Same happens when we share a printer with many computers.

Compiling a HLL code.

Using download manager, for multiple files also uses queue for ordering the files.

In multiuser OS – job scheduling is done through queue.

Question 8:Evaluate the following postfix notation of expression. Show status of stack after every operation.Answer:Final Result = 1

Question 9:Evaluatethefollowingpostixnotationofexpression. Show status of stack after every operation.12,2, *, 24,20, -, +, 8, –Answer:

Question 10:Give few applications of stack.Answer:

Expression evaluation

Backtracking (game playing, finding paths, exhaustive searching).

Memory management, run-time environment for nested language features.

Short Answer Type Questions-II (2 marks)

Question 1:Write an algorithm to evaluate postfix expression.Answer:Step 1: StartStep 2: Check all symbols from left to right and repeat steps 3 & 4 for each symbol of expression ‘E’ until all symbols are over.

If the symbol is an operand, push it onto stack.

If the symbol is an operator then:

Pop the top two operands from stack and apply an operator in between them.

Evaluate the expression and place the result back on the stack.

Step 3: Set result equal to top element on the stack.Step 4: Stop

Question 2:Write an algorithm to convert infix to postfix.Answer:

Create an empty stack and an empty postfix output string/stream.

Scan the infix input string/stream left to right.

If the current input token is an operand, simply append it to the output string (note the examples above that the operands remain in the same order).

If the current input token is an operator, pop off all operators that have equal or higher precedence and append them to the output string; push the operator onto the stack. The order of popping is the order in the output.

If the current input token is push it onto the stack.

If the current input token is ‘)’, pop off all operators and append them to the output string until a ‘(‘ is popped; discard the ‘(‘.

If the end of the input string is found, pop all operators and append them to the output string.

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NCERT Class 12 Computer Science Chapter 2 Object Oriented Programming Concepts

NCERT Class 12 Computer Science Python Solutions for Chapter 2 :: Object Oriented Programming Concepts

TOPIC-1

General OOP ConceptsShort Answer Type Questions (2 marks)

Question 1:How is a static method different from an instance method?Answer:Static method has to be defined outside a class. It can be called without an object.Instance method is defined within a class and has to be invoked on an object.

Question 2:Explain Data Hiding with respect to OOP.Answer:Data hiding can be defined as the mechanism of hiding the data of a class from the outside world or to be precise, from other classes. Data hiding is achieved by making the members of the class private. Access to private members is restricted and is only available to the member functions of the same class. However the public part of the object is accessible outside the class.

Question 3:Fill in the blanks:

Act of representing essential features without background detail is called ______ .

Wrapping up of data and associated functions into a single unit is called ______ .

______ is called the instance of a class.

Answer:

Data Abstraction

Encapsulation

Object

Question 4:What is Object Oriented Programming? List some of its advantages.Answer:OOP allows decomposition of a problem into a number of entities called objects and then builds data and functions around these objects. Advantages:

Simplicity

Modifiability

Extensibility and Maintainability

Reusability

Security

Question 5:Differentiate between an object and a class.Answer:A class is a collection of objects of similar type.For example, mango, apple and orange are members of the class fruit. Classes are user-defined data types and behave like the built-in types of a programming language.The syntax used to create an object is not different than the syntax used to create an integer object in C. If fruit has been defined as a class, then the statement fruit mango; will create an object mango belonging to the class fruit.

Question 6:Explain polymorphism with an example.Answer:Polymorphism is the ability for a message or data to be processed in more than one form. An operation may exhibit different behaviors in different instances. For example, consider the operation of addition of two numbers, the operation will generate a sum. If the operands are strings, then the operation would produce a third string by concatenation.

Question 7:List three features that make an important charac-teristic of OOP.Answer:

Capability to express closeness with the real- world models.

Reusability-allows addition of new features to an existing one.

Transitivity-changes in one class get automatically reflected across.

Question 8:How do we implement abstract method in python? Give an example for the same.Answer:Abstract method : An unimplement method is called an abstract method. When an abstract medhod is declared in a base class the derived class has to define the method or raise “Notimplemented Error”

Abstract Method can be used to enable parent class method execution.Class Shape (object):def findArea (self): passClass Square (Shape):def init (self, side):self, side = side def findArea self.side*self.side

Question 9:List few disadvantages of OOP.Answer:

Classes tend to be overly generalized.

Relationship among classes might become artificial.

Program design is tricky and complicated.

More skills and thinking in terms of objects is required.

Question 10:Explain Function overloading with an example.Answer:When several function declarations are specified for a single function name in the same scope, the function is said to be overloaded. In other languages, the same function name can be used to define multiple functions with different number and type of arguments, def test(): #function 1 print “hello”def test(a, b): #function 2return a+bdef test(a, b, c): #function 3return a+b+c 2

Question 11:What is inheritance? Explain with an example.Answer:Inheritance is the capability of one class to acquire the properties or capabilities of another class. For example, the bird ‘Parrot’ is a part of the class ‘Flying Bird’ which is again a part of the class ‘Bird’.

Question 12:How data encapsulation and data abstraction are implemented in Python, explain with an example.

How do abstraction and encapsulation complement each other?Answer:Abstraction and Encapsulation are complementary concepts. Through encapsulation only we are able to enclose the components of the object into a single unit and separate the private and public members. It is through abstraction that only the essential behaviors of the objects are made visible to the outside world.So, we can say that encapsulation is the way to implement data abstraction. For example in class Student, only the essential information like roll no, name, date_of_birth, course, etc. of the student will be visible. The secret information like calculation of grades, allotment of examiners etc. will be hidden.

Question 13:Consider the figure given below and answer the questions that follows:

Name the base class and the derived class.

Which concept of OOP is implemented in the figure given above?

Answer:

Base class – STUDENTDerived classes – GRADUATE & POST GRADUATE

Inheritance

Question 14:What is abstract method? Give a suitable example to illustrate the same.Answer:Abstract Method: An abstract method is a method defined in the base class, but does not require code for the implementaion. e.g.,Class teacher: def entry (self):teach#=int(input(“Enter No”))def display ( ):print (self, teach #)

Question 15:What is the concept of overriding method? Give an example for the same.Answer:Overriding Methods : It is a method to access, the paramterized constructer with same name but having different parameters. For example,Class emp:def_init_(self, n):self, a = n def_init_(self):self, a = 100

Question 16:Is function overloading supported by Python? Give reasons.Answer:A given name can only be associated with one function at a time, so cannot overload a function with multiple definitions. If you define two or more functions with the same name, the last one defined is used.However, it is possible to overload a function, or otherwise genericized it. You simply need to create a dispatcher function that then dispatches to your set of corresponding functions. Another way to genericized a function is to make use of the simple generic module which lets you define simple single-dispatch generic functions.def test(): #function 1print “hello”def test(a, b): #function 2return a+bdef test(a, b, c): #function 3return a+b+cIf you run the code of three test functions, the second test() definition will overwrite the first one. Subsequently the third test() definition will overwrite the second one. That means if you give the function call test (20,20), it will flash an error stating, “Type Error: add() takes exactly 3 arguments (2 given)”. This is because, Python understands the latest definition of the function test() which takes three arguments.

Question 17:Predict the output of the following program. Also state which concept of OOP is being implemented?def sum(x,y,z):print “sum= ”, x+y+zdef sum(a,b):print “sum= ”, a+bsum(10,20)sum(10,20,30)Answer:Type Error: sum() takes exactly 3 arguments (2 given)Concept: Polymorphism [Function Overloading]

Question 18:Define binding. Differentiate between static and dynamic binding.Answer:Binding is the process of linking the function call to the function definition. The body of the function is executed when the function call is made. Binding can be of two types:Static Binding: In this type of binding, the linking of function call to the function definition is done during compilation of the program.Dynamic Binding: In this type of binding, linking of a function call to the function definition is done at run time. That means the code of the function that is to be linked with function call is unknown until it is executed.

Long Answer Type Questions (4 marks)

Question 1:Write a program that uses an area() function for the calculation of area of a triangle or a rectangle or a square. Number of sides (3, 2 or 1) suggest the shape for which the area is to be calculated.Answer:from functools import wrapsimport mathdef overloaded(func):@wraps(func)def overloaded_func(*args, **kwargs):for f in overloaded_func.overloads:try:return f(*args, **kwargs)except TÿpeError:passelse:# it will be nice if the error message prints a list of# possible signatures hereraise TÿpeError(“No compatible signatures”)def overload_with(func):overloaded_func.overloads.append(func)return overloaded_funcoverloadedjunc.overloads = [func]overloaded_func.overload_with = overload_withreturn overloaded_func

#############©overloadeddef area():print ‘Area’[email protected]_withdef _(a):# note that, like property(), the function’s name in# the “def _(n):” line can be arbitrary, the important# name is in the “@overloads(a)” lineprint ‘Area of square=’,a*apass

@area.overload_withdef _(a,b):# note that, like property(), the function’s name in# the “def _(nl,n2):” line can be arbitrary, the important t# name is in the “@overloads(a)” lineprint Area of rectangle=’,a*[email protected]_withdef _(a.b,c):s= (a+b+c)/2print sprint Area of triangle=’, math.sqrt(s*(s-a)* (s-b)*(s-c))passchoice=input(“Enter 1-square 2-rectangle 3- tr-iangle”)if choice==1:side = input(“Enter side”) area(side)elif choice ==2:length = input(“Enter length”)breadth = input(“Enter breadth”)area(length,breadth) elif choice==3:a = inputfEnter sidel”)b = inputfEnter side2”)c = inputfEnter side3”) area(a,b,c)else:print “Invalid choice”

Question 2:Write a program to find out volume of a cube, cuboid and cylinder using function overloading.Answer:from functools import wraps import math def overloaded(func):@wraps(func)def overloaded_funcfargs, **kwargs):for f in overloaded_func.overloads:try:return ff args, **kwargs)except TypeError:pass 1else:# it will be nice if the error message prints a list of# possible signatures here raiseTypeError(“No compatible signatures”)def overload_with(func):overloaded_func.overloads.append(func)return overloaded_funcoverloaded_func.overloads = [func]overloaded_func.overload_with = overload_withreturn overloaded_func #############@overloadeddef volume():print ‘Volume’[email protected]_with def _(a):print ‘Volume of cube=’,a*a*a, ‘cubic units’[email protected]_with def _(a,b):print ‘Volume of cylinder, 3.14*a*a*b,‘cubic units’[email protected]_with def _(a,b,c):print ‘Volume of cuboid=’, a*b*c, ‘cubic units’passchoice = input(“Enter 1-cube 2-cylinder 3-cuboid”)if choice==1:side = input(“Enter side”)volume (side)elif choice ==2:radius = input(“Enter radius”)height = input( “Enter height”)volume(radius,height)elif choice==3:length = input(“Enter length”)breadth = input(“Enter breadth”)height = input(“Enter height”)volume (length, breadth, height)else:print “Invalid choice”

Question 3:Write a class CITY in Python with following specification :

Code # Numberic value

Name # String value

Pop # Numberic value for Population

KM # Numberic value

Density # Numberic value for Population DensityMethods:

CalDen ( ) # Method to calculate Density as Pop /KM

Record ( ) # Method to allow user to enter values Code, Name, Pop, KM and call CalDen ( ) method

See ( ) # Method to display all the date members also display a message “Highly Populated Area” is the Density is more than 12000.

Answer:class CITY:def _init_ (self):self. Code = 0self. Name =” ”self. Pop = 0self. KM = 0self. Density = 0def CalDen (self):self. Density = self. Pop/self. KMdef Record (self)self: Code = input (“Enter Code”)self.Name=raw_input(“Enter Name”)self. Pop = input (“Enter population”)self. KM = input (“Enter KM”)CalDen (self) // or self.CalDen ( )def See (self):print Code, name, Pop, KM, Densityif self. Density > 12000:print (“Highly Populated Area”)# OR print (“Highly populated Area”)Note : Accept self. _Cose to indicate private members

Question 4:Give a suitable example using Python code to illustrate single level inheritance considering COUNTRY to be BASE class and STATE to be derived class.Answer:Class COUNTRY: statejist = [ ]def_init_(self, name):self.name = name class state (COUNTRY):def_init_(self, name, capital): super ( )._init_(name)self.capital = capital

Question 5:Write a class DISTRICT in Python with following specification:Instance Attributes– Dcode # Numeric value– DName # String value– People # Numeric value for Population– Area # Numeric value– Density # Numeric value for Population DensityAnswer:Class DISTRICT ( ) :def_init_(self, Dcode, DName, People, Area, Density):self.Dcode = Dcodeself.DName = DNameself.People = Peopleself. Area = Areaself.Density = DensityDef display (self):print (“District Code”, self.Dcode)printf (“District Name”, self.Dname)printf (“Population”, self.people)printf (“Area”, self.Area)printf (“Density”, self.Denstity)

Question 6:Answer the question (i) to (iv) based on the following:Class Shop (object):Class shop_(self) :self . no_of _employees = 0self. no_of _brands= 0def getSdate (self) :self. no_of_employees=input(“Number of employees”)self.no_of_brands=input(”Number of brands”)def showSdate (self) :Print self.no of employeesPrint self.no of brands class Brand (object) :def init_(self) :self.name = ” ”self.category=(“Mens”, “Womens”, “Kids”)self.avgprice=0, 0def getdate (self) :self.name = raw_input(“Enter Brand Name”)self.avgprice = input(”Enter Average Price”)def showdate (self) :Print self, namePrint self, categoryPrint self, avgpriceClass Mall (Brand, Shop) :def showdate (self) :self.no of shops = 0def getdate (self) :super (mall, self).getSdate ( ) # Statementsuper (mall, self).getdate ( ) # Statement 2self.no_of_shops=input (“Enter number of shops”)def showdata(self)print self.no_of_shopsprint self.no of brands # Blank 1

Which type of inheritance is demonstrated in the above code?

Explain Statement 1 and 2.

Name the methods that are overridden along with their class name.

Fill Blank 1 with a statement to display variable category of class Brand.

Answer:

Multiple Inheritance

Statement 1 and 2 invoke the getSdate() function of class shop and getData() function of class Brand respectively.

getdata() method of class Brand is overridden. When object of class Mall is created.M=Mall ( )k.getdata ( )getdate( ) methodof class Mall is invoked and not of class Brand is called.

print Brand ( ). category

TOPIC-2ClassesShort Answer Type Questions (2 marks)

Question 1:Give one word for the following:a. A sort of constructor in Python ______b. A region of a Python program where a namespace is directly accessible.______c. It returns the docstring of a class.______d. It returns the string representation of the object. ______e. A method used to delete an attribute. ______Answer:a. _init_b. scopec. _doc_d. _str_e. _delattr_ ()

Question 2:Define a namespace. Give examples of namespaces with respect to Python.Answer:Namespace is a mapping from names to objects. Examples of namespaces are built-in names, global names in a module and local names in function invocation.

Question 3:What is the significance of super method? Give on example of the same.Answer:super ( ) function is used to call base class methods which has been extended in derived class.Example :class GradStudent (Student):def_ init _(self) :super (GradStudent, self). _init _( )self. subject = ” ”self. working = ” ”def readGrad (self) :# Call readStudent method of parent class super (GradStudent, self). readStudent ( )

Question 4:Explain LEGB rule.Answer:LEGB rule: when a name is encountered during the execution of the program , it searches for that name in the following order:L. Local – It first makes a local search, i.e. in current def statement.E. Enclosing functions – It searches in all enclosing functions, form inner to outer.G. Global (module) – It searches for global modules or for names declared globalB. Built-in (Python) – Finally it checks for any built in functions in Python.

Question 5:Is object of a class mutable? Why/why not?Answer:User classes are considered mutable. Python doesn’t have (absolutely) private attributes, so you can always change a class.

Question 6:Explain the usage of keyword ‘pass’ in class definition.Answer:When a class doesn’t define any methods or attributes, but syntactically, there needs to be something in the definition, so we use pass. It is a statement that does nothing, and is a good placeholder when you are stubbing out functions or classes.

Question 7:What is the use of _init_ ? When is it called? Explain with an example.Answer:

_init_ help to create objects and instances to the parent class.

It reserve the memory to the members of the class.

Question 8:Explain the importance of self in Python classes.Answer:self is an object reference to the object itself, therefore, they are same. Python methods are not called in the context of the object itself, self in Python may be used to deal with custom object models.

Question 9:Differentiate between class attributes and instance attributes.Answer:The difference is that the attribute on the class is shared by all instances. The attribute on an instance is unique to that instance.

Question 10:Explain _str_ with an example.Answer:_str_ , returns a string representation of a Point object. If a class provides a method named _str_ , it overrides the default behavior of the Python built-in _str_ function.>>> p = Point(3, 4)>>> str(p)‘(3,4)’Printing a Point object implicitly invokes _str_ on the object, so*- defining _str_ also changes the behavior of print:>>> p = Point(3,4)>>> print p(3,4)

Question 11:What do you mean by name mangling? Support your answer with relevant example.Answer:Name mangling of the double underscore makes the most sense for achieving “private-ness”. Now when a function is called from the ‘self’ instanceand it notices that it starts with ‘_’, it just performs the name mangling right there. Name mangling is helpful for letting sub-classes override methods without breaking intra class method calls.

Question 12:Differentiate between reference counting and automatic garbage collection with respect to Python.Answer:Reference counting works by counting the number of times an object is referenced by other objects in the system. Python’s garbage collector runs during program execution and is triggered when an object’s reference count reaches zero. An object’s reference count changes as the number of aliases that point to it change. An object’s reference count increases when it is assigned a new name or placed in a container (list, tuple or dictionary). The object’s reference count decreases when it is deleted with del, its reference is reassigned, or its reference goes out of scope. When an object’s reference count reaches zero, Python collects it automatically.Automatic garbage collectiomPython deletes the objects which are not required, may it be built-in types or class instances, through the process named garbage collection. When the number of allocations minus the number of de-allocations are greater than the threshold number, the garbage collector is run and the unused block of memory is reclaimed.One can inspect the threshold for new objects by loading the garbage collector (gc) module and asking for garbage collection thresholds.

Question 13:Predict the output of the following code snippet:ptr=40def result():print ptrptr=90def func(var):if var<=60:ptr=30print ptrresult()func(60)func(70)Answer:UnboundLocalError: local variable ‘ptr’ referenced before assignment.

Question 14:What is the difference between Multilevel inheritance and multiple inheritance? Give suitable examples to illustrate.Answer:

Question 15:How do you implement abstract method in Python? Give an example for the same.Answer:Abstract method : An unimplemented method is an abstract method. When an abstract method is declared in a base class, the drived class has to either difine the method or raise” Nothlmplemented Error”class Shape (object):def findArea (self):passclass Square (Shape):def_ init_(self, side):self, side = sidedef find Area (self):return self.side*self.sideNote: We can use @ abstract method to enable parent class method to be executed.

Question 16:Predict the output of the following code snippet:ptr=50def result():global ptrptr=ptr+1print ptr result()print ptrAnswer:5151

Question 17:Name the methods that can be used to:

access attribute of an object

delete an attribute of an object

Answer:

getattr(obj, name[, default])

delattr(obj, name)

Question 18:Give the statement to:

Check whether the attribute str exists in the class Test whose object is T

Assign a value “Hello” to the attribute str of class Test and object Tl.

Answer:

hasattr (Tl,str)

setattr (Tl, str, “Hello”)

Question 19:Predict the output of the following code:class Match:#“Runs and Wickets”runs=281wickets=5def init (self,runs, wickets) :self.runs=runsself.wickets=wicketsprint “Runs scored are :” ,runsprint “Wickets taken are :” .wicketsprint “Test. do :”, Match. docprint “Test._name_ , Match. _name_print “Test_module_ , Match.__module_print “Test. _bases_ , Match._bases_print “Test._dict_ , Match. _diet_Answer:Runs scored are : 281Wickets taken are : 5Test._ do_ : NoneTest._name_ : MatchTest._module_ : mainTest._bases_ : ()Test. _diet_ : {‘ _module _’: ‘_ main_ ’, ‘_doc _’: None, ‘runs’: 281, ‘_init_ ’:<function _init_ at 0x0000000002DDFBA8>, ‘wickets’: 5}

Long Answer Type Questions (4 marks)

Question 1:Write a class customer in Python Containing Deduct % Mark to be deducted if caldiscount () is following specifications. not invoked properly

Instance attributes: inside input( ) functioncustomernumber – numeric value No mark to be deducted if member functioncustomemame – string value definitions are written inside the class

price, qty discount, totalprice, netprice – numeric valuemethods :

init()-To assign initial values of customernumber as 111, customemame as “Leena”, qty as 0 and price, discount & netprice as 0.

caldiscount ( ) – To calculate discount, totalprice and netpricetotalprice = price * qty

discount is 25% of totalprice, if totalprice >=50000

discount 15% of totalprice, if totalprice >=25000 and totalprice <50000

discount 10% of totalprice, if totalprice <250000netprice= totalprice – discount

input()-to read data members customer- name, customernumber, price, qty and call caldiscount() to calculate discount, totalprice and netprice.

show( ) – to display Customer details.

Answer:

class customer:def _init_(self):self.customemumber=111self.customemame=‘Leena’self.qty=0self.price=0self.discount=0self.netprice=0def caldiscount(self):totalprice = self.price*self.qtyif totalprice >= 50000:self.discount=totalprice * 0.25elif totalprice >= 25000:self.discount = totalprice * 0.15 else:self.discount = totalprice * 0.10self.netprice = totalprice – self.discountdef input(self):self.customernumber=input(“Enter Customer Number”)self.customemame = raw_input(“Enter Customer Name”)self.qty = input(“Enter Quantity”)self.price = input(“Enter Price”)self.caldiscount()def show(self):print “Customer Number”,self.customernumberprint “Customer Name”,self.customemameprint “Quantity”,self.quanti-typrint “Price”,self.priceprint “Discount”,self.discountprint “Net price”,self.netpricec = customer()c.inputO c.show()

Question 2:Create the class SOCIETY with following information:society_name,house_no,no_of_members,flat, incomeMethods :

An _init_ method to assign initial valuesof society_name as “Surya Apartments”, flat as “AType”, house_.no as 20, no_of_ members as 3, income as 25000.

Inputdata()-To read data members(society,house_no,no_of members & income) and call allocate_flat().

allocate_flat( )-To allocate flat according to income

ShowData() to display the details of the entire class.

Answer:class SOCIETY:# constructor to create an objectdef init (self):#constructorself. society_name=‘Surya Apartments’self.house_no=20self.no_of_members=3self.flat=AType’self.income=25000def Inputdata(self):self. society_name = raw_input (“Enter Society Name”)self.house_no=input(“Enter House Number”)self.no_of_members = input (“Enter No. of members”)self.income = float(raw_input (“Enter income”))def Allocate_Flat(self):if self.income >= 25000:self.flat = AType’elif self.income >= 20000 and self.income < 25000 :self.flat = ‘BTÿpe’ else:self.flat = ‘CType’def Showdata(self):print “Society Name”,self.society_nameprint “House_No”,self.house_no print “No.of members”,self.no_of mem-bersprint “Flat Type”,self.flat print “Income”,self.incomeS = SOCIETY))S.InputdataOS.Allocate_Flat()S.ShowdataO

Question 3:Define a class ITEMINFO in Python with the following description:ICode (Item Code), Item (Item Name), Price (Price of each item), Qty (quantity in stock)Discount (Discount percentage on the item), Netprice (Final Price)Methods

A member function FindDisc( ) to calculate discount as per the following rules:If Qty< = 10Discount is 0If Qty (11 to 20)Discount is 15If Qty > =20Discount is 20

A constructor init method) to assign the value with 0 for ICode, Price, Qty, Netprice and Discountand null for Item respectively

A function Buy( ) to allow user to enter values for ICode, Item, Price, Qty and call function FindDisc( )to calculate the discount and N etprice(Price * Qty-Discount).

A Function ShowAll( ) to allow user to view the content of all the data members.

Answer:class ITEMINFO:#constructor to create an .objectdef_init_(self):#constructorself.ICode=0self.Item=‘ ’self.Price=0.0self.Qty=‘ ’self.Discount=0self.Netprice=0.0def Buy(self):self.ICode=input(“Enter Item Code”)self. Item=raw_input(“Enter Item Name”)self.Price=float(raw_input(“Enter Price”))self.Qty=input(“Enter Quantity”)def FindDisc(self):if self.Qty <= 10:self.Discount = 0elif self.Qty >= 11 and self.Qty < 20 :self.Discount = 15else:self.Discount = 20self.Netprice= (self.Price*self.Qty)self.Discountdef ShowAll(self):print “Item Code’’,self.ICodeprint “Item Name”,self.Itemprint “Price”,self.Priceprint “Quantity”,self.Qtyprint “NetPrice”,self.NetpriceI = ITEMINFO()I.Buy()I.FindDisc()I. Show All ()

Question 4:Define a class PRODUCT in Python with the following specifications :Data members:Pid – A string to store product.Pname -A string to store tha name of the product. Peostprice – A decimal to store the cost price of the productPsellingprice – A decimal to store Selling Price Margin- A decimal to be calculated as Psellingprice- PcostpriceRemarks- To store “Profit” if Margin is positive else “Loss’ if Margin is negativeMember Functions :

A constructor to intialize All the data members with valid default values.

A method SetRemarks() that assigns Margin as Psellingprice – Peostprice and sets Remarks as mentioned below :

A method Getdetails() to accept values for Pid. Pname,Psellingprice and invokes SetRemarks() method.

A method Setdetails () that displays all the data members.

Answer:class PRODUCT:def init (self):self. Pid = self. Pname = self. Peostprice = 0.0 self. Psellingprice = 0.0 self. Margin = 0.0 self. Remarks = def SetRemarks (self) :self . Margin = self.Psellinrprice-self. Peostpriceif (self.Margin < 0) :self. Ramarks = “Loss”else:self. Remarks = “Profit” defGetdetails (self):self.Pid = rawjnput (“Enter Product Id”)self.Pname = rawjnput (“Enter Product Name”)self.Peostprice = input (“Enter Cost Price”)self.Psellingprice = input (“Enter Selling Price”)self. SetRemarks ( ) def Setdateils (self) :print “Product Id” ,self.Pid print “Product Name”,self.Pname print “Cost Price”,self.Pcostprice print “Selling Price”,self.Esellingprice print “Margin : ” ,self.Margin print “Incurred :” ,self.Remarks

Question 5:Write a Python program using classes and objects to simulate result preparation system for 20 students. The data available for each student includes: Name, Rollno, and Marks in 3 subjects. The percentage marks and grade are to be calculated from the following information:Also demonstrate constructor overloading.Answer:# constructor to create an objectdef init (self,s=None):#non-copy constructor if s==None:self.rollno = 0 self.name = ‘ ’self.marks = [0,0,0]self.avg = 0.0 self.grade = ‘ ’# copy constructor else:self.rollno = s.rollno self.name = s.name self.marks = s.marks self.avg = s.avgself.grade = s.gradedef read (self):# This function gets the details of a student from the userselfrollno=iaw_input(“Enter roll number.-’)self.name = raw_input(“Enter name:-”) s=0for i in range(0,3):self.marks [i] = int(r a w_input (“Enter the marks ?”)) s = s + self.marksfi] self.avg = s/3if(self.avg>60):self.grade=‘A’elif self.avg>40:self.grade=‘B’else:self.grade=‘C’def display (self):# This function prints each student’s detailsprint self.rollno,“\t”, self, name, “\t\ t”,self.grade s = StudentO studlist = []num = int(raw_input(“Enter no. of students:-’’))for i in range(O.num):s.read()studlist. append(Student(s))print “ STUDENT REPORT \n”print “***********************************\n”print “RollNo \t Name \t\t Grade”print “*******************************************\n”for i in range(0,num):studlist[i] .displayO#Initialize avg as the first student’s avg maxavg = studlist[0].avg totavg = 0for i in range(l.num):totavg = totavg + studlist[i].avg if studlist[i].avg > maxavg: maxavg = studlist[i].avg topper = studlist[i].name totavg = totavg/numprint “Class topper is”,studlist[i],name,“with average”, studlist [i]. avgprint “Class average is”,totavgclass Student:

Question 6:Define a class SUPPLY in Python with the following description:Private Members Code of type int FoodName of type string FoodType of type string Sticker of type stringA member function GetType() to assign the following values for Food Type as per the given Sticker

A function Foodln() to allow user to enter values for Code, EoodName, Sticker and call function GetType() to assign respective FoodType.

A function FoodOut() to allow user to view the contents of all the data members.

Answer:class SUPPLY:• constructor to create an objectdef init (self) :#constructorself.FoodCode=()self.FoodName=‘ ’self.FoodType=‘ ’self.Sticker=‘ ’def Foodln(self):self.FoodCode=input(“Enter Food Code”)self.FoodName=raw_input(“Enter Food Name”)self.Sticker=raw_input(“Enter Sticker Colour”)def GetType(self):if self.Sticker==‘GREEN’:self.FoodType = ‘Vegetarian’elif self.Sticker==’YELLOW’:self.FoodType = ‘Contains Egg’elif self.Sticker==‘RED’:self.FoodType = ‘Non-Vegetarian’ else:self.FoodType = ‘Not Known’def FoodOut(self):print “FoodCode’’,self.FoodCodeprint “FoodName”,self.FoodNameprint “FoodType”,self.FoodTypeprint “Sticker”,self.StickerS = SUPPLY()S.FoodIn()S.GetTÿpe()S.FoodOut()

TOPIC-3InheritanceVery Short Answer Type Questions (1 mark)

Question 1:Give one example for an abstract method.Answer:An abstract method is a method declared in a parent class, but not implemented in it. The implementation of such a method can be given in the derived class, class circle(object):def getradius(self):

Question 2:Define the term inheritance.Answer:Inheritance is a mechanism in which a new class is derived from an already defined class. The derived class is known as a subclass or a child class. The pre-existing class is known as base class or a parent class or a super class. The mechanism of inheritance gives rise to hierarchy in classes. The major purpose of inheriting a base class into one or more derived class is code reuse. The subclass inherits all the methods and properties of the super class.

Question 3:What is single inheritance?Answer:In single inheritance a subclass is derived from a single base class.

Question 4:What is multiple inheritance? Explain with an example.Answer:In this type of inheritance, the derived class inherits from one or more base classes. In the figure below, X and Y are the base classes while Z is the derived class.

Question 5:Give one example of multilevel inheritance.Answer:In multilevel inheritance, the derived class becomes the base of another class.For example, Country is the base class of State and City is the derived class of State.

Short Answer Type Questions (2 marks)

Question 1:Based on the diagram, answer the following:

Write the name of the base class and the derived classes.

Write the type of inheritance depicted in the above diagram.

Answer:

Base class – Furniture; Derived classes – Sofa & Cot

Hierarchical inheritance

Question 2:Explain the concept of overriding methods.Answer:Overriding is a very important part of OOB since it is the feature that makes inheritance exploit its full power. Through method overriding, a class may “copy” another class, avoiding duplicated code, and at the same time enhance or customize part of it.

Question 3:Based on the diagram, answer the following:

Write the name of the base class and derived class of state.

Write the type of inheritance depicted in the diagram.

Answer:

Base class of state – CountryDerived class of state – City

Multilevel inheritance

Question 4:What are the different ways of overriding function call in derived class of python? Illustrate with example.Answer:Overriding enables the programmer to provide specific implementation to a method in the derived class. So, the method invoked depends on the object used to invoke it. If base class object is used then base class version of the method is called else the derived class method is called, class Parent:def func(self):print ‘Parent method’ class child:def func(self):print ‘child method’C = child()c.func() # child calls overridden method

Question 5:How do we implement abstract method in Python?Support your answer with an example.Answer:An abstract method is a method defined in a base class, but that may not provide any implementation. It is done by using the abc module in Python, import abcclass Shape(object):metaclass = [email protected] method_to_implement(self, input):“’’’’Method documentationreturn

Question 6:Find the output of the following code and write the type of inheritance:p=Gstudent(‘Mona’, 20,12, $9, ‘computer’)def_init_(self, name, age, roll no, marks, stream):super (Gstudent, self) _init_(name, age, roll no, marks)self stream=streamdef display 2 (self):self display()print “stream:”,self.stream P=Gstudent (‘Mona’, 20,12, 99, ‘Computer’)p.display2()Answer:TVpe of inheritance: Multilevel Output:Name : MonaAge : 20Roll No: 12Marks : 99stream: computer

Question 7:Rewrite the following code after removing errors. Underline each correction and write the output after correcting the code:class First():def _init_ (self):print “first”:class Second(object):def _init_ (self):print “second” class Third(First, Second):def _init_ (self):First. _init_ (self):Second. _init_ (self):print “that’s it”t=Third()t=Third()Answer:class First():def _init_ (self):print “first”class Second(object):def_ init_(self):print “second” class Third(First, Second):def _init_ (self):First._init_ (self)Second._init_(self)print “that’s it”t=Third()t=Third()

Question 8:Complete the following code:class employee(object):def _init_(self,no,name,age):self.no=noself.name=___ #complete the statementself.age= ___ #complete the statementdef printval(self):print “Number:”,self.no print “Name :”,self.name print “Age :”,self.age class pay(object):def _init_ (self,dept,salary): #completethe definition__________________def display(self): #complete the definition______ # call printval()______ # print dept______ # print salaryAnswer:class employee (object):def init (self,no,name,age):self.no=noself.name=nameself.age=agedef printval(self):print “Number:”,self.no print “Name :”,self.nameprint “Age :’’,self.ageclass pay(object):def _init_ (self,dept,salary):self.dept =deptself.salary=salarydef display(self)self.printval()print self.deptprint self.salary

Long Answer Type Questions (4 marks)

Question 1:Write a Python program to demonstrate multiple inheritance. Consider 3 classes with the following description.Student class has 3 protected data members roll number, markl and mark2 of type integer. It has a get() function to get these details from the user. Sports class has a protected data member sports marks of type integer and a function getsm() to get the sports mark.Statement class uses the marks from Student class and the sports marks from the Sports class to calculate the total and average and displays the final resultAnswer:class student(object):# constructor to create an object def init (self):self.mo=0self.m1=0self.m2=0def get(self):self.mo=int(raw_input(“Enter the Roll no:”))print “Enter 2 marks”self.m1=int(raw_input(“Markl?”))self.m2=int(raw_input(“Mark2 ?”))classsports(object):# Sports markdef_init_(self):self.sm=0def getsm(self):self.sm=int(raw_input(“Enter the sports mark:”))class statement(student,sports):def_init_(self):super(statement,self)._init_()def display (self):tot=(self.ml+self.m2+self.sm); avg=tot/3;print“\n\n\tRoll No. : ”,self.mo,“\n\tTotal :”,tot print“\tAverage : ”,avgobj=statement()obj.get()obj.getsm()obj. display()

Question 2:SKP Hotel offers accommodation, meals facilities.Create a class Accommodation with Room Number, type of room, and rent, etc..Create a class meals services includes: meals code, name, price, etc..Create a class customer with customer number, name, address, etc.Customer class is derived by using Accommodation and meals classes.Answer:class Accommodation(object):# constructor to create an objectdef_init_(self):self.roomno=0self.roomtype=”self.roomrent=0.0defgetroom(self):self.roomno=input(“Enter the Room no:”)self.roomtype=rawjnput(“Enter the Room type:’)self.roomrent=float(raw_input(“Enter Room Rent”))class Meals(object):# Meals classdef_init_(self):self.mealcode=0self.mealname=“”self.mealprice=0.0def getmeals(self):self.mealcode=input(“Enter the meal code:”)self.mealname=raw_input(“Enter the meal name:”)self.mealprice=float(raw_input(“Enter the meal price”))class Customer(Accommodation,Meals):def_init_(self):super(Customer,self)._init_()self.custnum=0self.custname=‘ ’self.address=‘ ’def getCustomer(self):self.custnum=input(“Enter the customer number”)self.custname=raw_input(“Enter customer name”)self. address=raw _input(“Enter customer address”)def displaybill(self):print“Customer Name:”,self.custname,“Address:”, self, addressprint“Room No:”,self.roomno,“Room Type:”,self.roomtype,“Room Rent: Rs’jself.roomrentprint“Meal Name:”,self.mealname,“Price:”,self.mealpriceprint“Total Amount Due:”,self.roomrent+ self.mealpriceobj=Customer()obj.getCustomer()obj.getroom()obj.getmeals()obj.displaybill()

Question 3:Pay roll information system:Declare the base class ’employee’ with employee’s number, name, designation, address, phone number. Define and declare the function getdata() and putdata() to get the employee’s details and print employee’s details. Declare the derived class salary with basic pay, DA, HRA, Gross pay, PF, Income tax and Net pay. Declare and define the function getdatal() to call getdata() and get the basic pay. Define the function calculate() to find the net pay. Define the function display() to call putdata() and display salary details .Create the derived class object. Read the number of employees. Call the function getdatal)) and calculate() to each employees. Call the display() function.Answer:class employee (object):# constructor to create an objectdef init (self):self.eno=0self.name=‘ ’self.designation=‘ ’self.address = ‘ ’self.phonenumber=0def getdata(self):self.eno=input(“Enter Employee Number”)self.name=raw_input(“Enter Employee Name’)self.designation=raw_input(“Enter Employee Designation”)self.address = raw_input(“Enter Employee Address”)self.phonenumber=input(“Enter Employee Phone Number”)def putdata (self):print “Employee Number”,self.enoprint “Employee Name”,self.nameprint “Employee Designation”,self.designationprint “Employee Address”,self.addressprint “Employee Phone Number”,self phonenumberclass salary (employee):# Salary detailsdef_init_(self):super(salaryself)._init_()self.basic=0self.DA=0self.HRA=0self.Gross=0self.PF=0self.tax=0self.netpay=0def getdatal(self): self.getdata()self.basic=float(raw_input(“Enter the basic pay’’))self.DA=float(raw_input(“Enter the DA”))self.HRA=float(raw_input(“Enter the HRA))self.PF = float(raw_input(“Enter the PF”))def calculate(self):self.Gross= self.basic + self.FîRA + self.DAif .self. Gross < 100000:self.tax=0elif self.Gross < 500000:self.tax=self.Gross*0.10elif self.Gross < 1000000:self.tax=self.Gross*0.15else:self.tax=self.Gross*0.20self.netpay= self.Gross – self.PF – self.taxdef display(self):self.putdataOprint “Gross Income”,self.Grossprint “Tax “,self.taxprint “Net Income”,self.netpaysalaryobj =salary()num = int(raw_input(“Enter no. of employees:-”))for i in range(0,num):salaryobj.getdatal()salaryobj.calculate()salaryobj.display()

Question 4:Define a class employee in Python with the given specifications:Instance variables:Employee number, name Methods:Getdata()- To input employee number and namePrintdata()- To display employee number and nameDefine another class payroll, which is derived from employeeInstance variable Methods:Inputdata() – To call Getdata() and input salary.Outdata() – To call Printdata() and to display salary.Define another class leave, which is derived from payroll.Instance variable No of days Methods:acceptdata() – To call Inputdata() and input no of days.showdata() – To call Outdata() and to display no of days.Implement the above program in python.Answer:class Employee(object):# constructor to create an objectdef_init_(self):self.eno=0self.name=“”def Getdata(self):self.eno=input(“Enter the Employee no:”)self.name= raw_input(“Enter the Employee Name:”)def Printdata(self):print “Employee Number”,self.eno print “Employee Name”,self.nameclass payroll(Employee):def_init_(self):super(payroll,self). _init_()self.salary=0def Inputdata(self): self.GetdataQself.salary=float(raw_input(“Enter the salary:”))def Outdata(self): self.Printdata()print “Salary is”,self.salaryclass leave(payroll):def_init_(self):super(leave,self)._init_()self.Noofdays=0 def acceptdata(self):self.Inputdata()self.Noofdays =input(“Enter leave days”)def showdata(self): self.Outdata()print “No. of leave days”,self.Noofdays leaveobj = leave()leaveobj. acceptdataOleaveobj.showdata()

Question 5: What output will be generated when the following Python code is executed?def changeList () :L = []LI = [ ]L2 = []for i in range (10,1, -2) :LI append (i)for i in range (len ( LI)) :L2. append (LI [i] + L [i] )print L2ChangeList ( )Answer:[11, 10,9, 8, 7,4]

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NCERT Class 12 Computer Science Chapter 1 Review of Python

NCERT Class 12 Computer Science Python Solutions for Chapter 1 :: Review of Python

TOPIC-1

Python Basics

Very Short Answer Type Questions(1 mark)

Question 1.Name the Python Library modules which need to be imported to invoke the following functions:

load ()

pow () [CBSE Delhi 2016]

Answer:

pickle

math

Question 2.Name the modules to which the following func-tions belong:

Uniform ()

fabs () [CBSE SQP 2016]

Answer:

random ()

math ()

Question 3.Differentiate between the round() and floor() functions with the help of suitable example.[CBSE Comptt. 2016]Answer:The function round() is used to convert a fractional number into whole as the nearest next whereas the function floor() is used convert to the nearest lower whole number, e.g.,round (5.8) = 6, round (4.1) = 5 and floor (6.9) = 6, floor (5.01) = 5

Short Answer Type Questions (2 marks):

Question 1.Out of the following, find those identifiers, which cannot be used for naming Variables or functions in a Python program:Total * Tax, While, Class, Switch, 3rd Row, finally, Column 31, Total. [CBSE Outside Delhi-2016]Answer:Total * Tax, class, 3rd Row, finally

Question 2.Name the Python Library modules which need to be imported to invoke the follwing functions :

sqrt()

dump() (CBSE Outside Delhi-2016)

Answer:

math

pickle

Question 3.Out of the following, find the identifiers, which cannot be used for naming Variable or Functions in a Python program: [CBSE Delhi 2016]_Cost, Price*Qty, float, switch, Address one, Delete, Number12, doAnswer:Price *Qty, float, Address one, do

Question 4.Out of the following find those identifiers, which can not be used for naming Variable or Functions in a Python Program:Days * Rent, For, A_price, Grand Total, do, 2Clients, Participantl, My cityAnswer:Illegal variables or functions name are as below: Days * Rent, do, 2Clients, For and Grant Total Because of being either keyword or including space or operator or starting with integar.

Question 5.Name the function / method required for [CBSE SQP 2015]

Finding second occurrence of m in madam.

get the position of an item in the list.

Answer:

find

index

Question 6.Which string method is used to implement the following:

To count the number of characters in the string.

To change the first character of the string in capital letter.

To check whether given character is letter or a number.

To change lowercase to uppercase letter.

Change one character into another character. [CBSE TextBook]

Answer:

len(str)

str.capitalize()

ch.isalnum()

str.upper()

str.replace(old,new)

Question 7.What is the difference between input() and raw_input()?Answer:raw_input() takes the input as a string whereas input() basically looks at what the user enters, and automatically determines the correct type. We use the inputQ function when you are expecting an integer from the end-user, and raw_input when you are expecting a string.

Question 8.What are the two ways of output using print()?Answer:Ordinarily, each print statement produces one line of output. You can end the print statement with a trailing ’ to combine the results of multiple print statements into a single line.

Question 9.Why does the expression 2 + 3*4 result in the value 14 and not the value 24?Answer:Operator precedence rules* make the expression to be interpreted as 2 + (3*4) hence the result is 14.

Question 10.How many times will Python execute the code inside the following while loop? You should answer the question without using the interpreter! Justify your answers.

i = 0 while i < 0 and i > 2 : print “Hello ...” i = i+1

Answer:0 times.

Question 11.How many times will Python execute the code inside the following while loop?

i = 1 while i < 10000 and i > 0 and 1: print “ Hello ...” i = 2 * i

Answer:14.

Question 12.Convert the following for loop into while loop, for i in range (1,100):

if i % 4 == 2 : print i, “mod”, 4 , “= 2”

Answer:

i=1 while i < 100: if i % 4 == 2: print i, “mod”, 4 , “= 2” i = i +1

Question 13.Convert the following for loop into while loop.

for i in range(10): for j in range(i): print '$', print"

Answer:

i=0 while i < 10: j=0 while j < i: print '$’ print"

Question 14.Rewrite the following for loop into while loop: [CBSE Text Book]

for a in range(25,500,25): print a

Answer:

a=25 while a < 500: print a a = a + 25

Question 15.Rewrite the following for loop into while loop: [CBSE Text Book]

for a in range(90, 9, -9): print a

Answer:

a = 90 while a > 9: print a a = a-9

Question 16.Convert the following while loop into for loop:

i = 0 while i < 100: if i % 2 == 0: print i, “is even” else: print i, “is odd” i = i + 1

Answer:

for i in range(100): if i % 2 == 0: print i, “is even” else : print i, “is odd”

Question 17.Convert the following while loop into for loop

char = "" print “Press Tab Enter to stop ...” iteration = 0 while not char == “\t” and not iteration > 99: print “Continue?” char = raw_input() iteration+ = 1

Answer:

char = "" print “Press Tab Enter to stop ...” for iteration in range(99): if not char == ‘\t’: print “Continue?” char = raw_input()

Question 18.Rewrite the following while loop into for loop:

i = 10 while i<250: print i i = i+50

Answer:

for i in range(10, 250, 50): print i

Question 19.Rewrite the following while loop into for loop:

i=88 while(i>=8): print i i- = 8

Answer:

for i in range(88, 9, -8) print i

Question 20.Write for statement to print the series 10,20,30, ……., 300Answer:

for i in range(10, 301, 10): print i

Question 21.Write for statement to print the series 105,98,91,… .7Answer:

for i in range(105, 8, -7): print i

Question 22.Write the while loop to print the series: 5,10,15,…100Answer:

i=5 while i <= 100: print i i = i + 5

Question 23.How many times is the following loop executed? [CBSE Text Book]for a in range(100,10,-10):print aAnswer:9 times.

Question 24.How many times is the following loop executed? [CBSE Text Book]

i = 100 while (i<=200): print i i + =20

Answer:6 times

Question 25.State whether the statement is True or False? No matter the underlying data type if values are equal returns true,

char ch1, ch2; if (ch1==ch2) print “Equal”

Answer:True. Two values of same data types can be equal.

Question 26.What are the logical operators of Python?Answer:or, and, not

Question 27.What is the difference between ‘/’ and ‘//’ ?Answer:

// is Integer or Floor division whereas / is normal division (eg) 7.0 // 2 → 3.0 7.0/2 → 3.5

Question 28.How can we import a module in Python?Answer:1. using import

Syntax: import[,,...] Example: import math, cmath

2. using from

Syntax: fromimport[, ,.. ,] Example: . from fib. import fib, fib2.

Question 29.What is the difference between parameters and arguments?Answer:

S.No.ParametersArguments1Values provided in function headerValues provided in function call.2(eg) def area (r):—> r is the parameter(eg) def main() radius = 5.0 area (radius)—> radius is the argument

Question 30.What are default arguments?Answer:Python allowes function arguments to have default values; if the function is called without the argument, the argument gets its default value

Question 31.What are keyword arguments?Answer:If there is a function with many parameters and we want to specify only some of them in function call,then value for such parameters can be provided by using their names instead of the positions. These are called keyword argument.

(eg) def simpleinterest(p, n=2, r=0.6) ' def simpleinterest(p, r=0.2, n=3)

Question 32.What are the advantages of keyword arguments?Answer:It is easier to use since we need not remember the order of the arguments.We can specify the values for only those parameters which we want, and others have default values.

Question 33.What does “in” do?Answer:“in” is a membership operator. It evaluates to true if it finds a variable/string in the specified sequence :Otherwise i+evaluates to false.

(eg) S = “Hello World" if “Hell” in S: print “True” will print True.

Question 34.What does “not in” do?Answer:“not in” is a membership operator. It evaluates to true if it does not finds a variable/stringin the specified sequence. Otherwise it evaluates to false,

(eg) S = “Hello World” if “Hell” not in S: print “False” will print False.

Question 35.What does “slice” do?Answer:The slice[n:m] operator extracts subparts from a string. It doesn’t include the character at index m.

(eg) S = “Hello World” print s[0:4] → Hell

Question 36.What is the use of negative indices in slicing?Answer:Python counts from the end (right) if negative indices are given.

(eg) S = “Hello” print S[:-3] >> He print S[-3:] >> llo

Question 37.Explain find() function?Answer:find (sub[,start[,end]])This function is used to search the first occurrence of the substring in the given string.It returns the index at which the substring starts. It returns -1 if the substring doesn’t occur in the string.

(eg) str = “computer” - str.findf("om”) → 1

Question 38.What are the differences between arrays and lists?Answer:An array holds fixed number of values. List is of variable-length – elements can be dynamically added or removedAn array holds values of a single type. List in Python can hold values of mixed data type.

Question 39.What is the difference between a tuple and a list?Answer:A tuple is immutable whereas a list is a mutable.A tuple cannot be changed whereas a list can be changed internally.A tuple uses parenthess (()) whereas a list uses square brackets ([]).tuple initialization: a = (2, 4, 5)list initialization: a = [2, 4, 5]

Question 40.Carefully observe the following python code and answer the question that follows:x=5def func2():x=3global xx=x+1print xprint xOn execution the above code produces the following output.63Explain the output with respect to the scope of the variables.Answer:Names declared with global keyword have to be referred at the file level. This is because the global scope.If no global statement is being used the variable with the local scope is accessed.Hence, in the above code the statement succeeding the statement global x informs Python to incrementthe global variable xHence, the output is 6 i.e. 5 + 1 which is also the value for global x.When x is reassingned with the value 3 the local x hides the global x and hence 3 printed.(2 marks for explaning the output) (Only 1 mark for explaining global and local namespace.)

Question 41.Explain the two strategies employed by Python for memory allocation. [CBSE SQP 2016]Answer:Pythonuses two strategies for memory allocation-(i) Reference counting(ii) Automatic garbage collectionReference Counting: works by counting the number of times an object is referenced by other in the system.When an object’s reference count reaches zero, Python collects it automatically.Automatic Garbage Collection: Python schedules garbage collection based upon a threshold of object allocations and object deallocations. When the number of allocations minus the number of deallocations are greater that the threshold number, the garbage collector is run and the unused blocks of memory is reclaimed.

TOPIC – 2Writing Python Programs

Question 1.Rewrite the following code in Python after removing all syntax errors(s). Underline each correction done in the code. [CBSE Delhi-2016]for Name in [Amar, Shveta, Parag]if Name [0] = ‘s’:Print (Name)Answer:

for Name in [“_Amar”, ”_Shveta_” , "_Parag_”] : if Name [0] E == ‘S’ : Print (Name)

Question 2.Rewrite the following code is Python after removing all syntax errors(s).Underline each correction done in the code. [CBSE Outside Delhi-2016]for Name in [Ramesh, Suraj, Priya]if Name [0] = ‘S’:Print (Name)Answer:

for Name in [“_Ramesh_”, “_Suraj_” , “_Priya_”] if Name [0] =_=‘S’ : print (Name)

Question 3.What will be the output of the following python code considering the following set of inputs?AMARTHREEA1231200Also, explain the try and except used in the code.Start = 0while True :Try:Number = int (raw input (“Enter Number”))breakexcept valueError : start=start+2print (“Re-enter an integer”)Print (start)Answer:Output:

Enter Number AMAR Re-enter an integer Enter Number THREE Re-enter an integer Enter Number A123 Re-enter an integer Enter Number 12006

Explanation : The code inside try makes sure that the valid number is entered by the user.When any input other an integer is entered, a value error is thrown and it prompts the user to enter another value.

Question 4.Give the output of following with justification. [CBSE SQP 2015]

x = 3 x+ = x-x print x

Answer:Output: 3Working:

x = 3 x = (x+ x-x ):x = 3 + 3 - 3 = 3

Question 5.What will be printed, when following Python code is executed? [CBSE SQP 2015]

class person: def init (self,id): self.id = id arjun = person(150) arjun. diet [‘age’] = 50 print arjun.age + len(arjun. diet )

Justify your answer.Answer:52arjun.age = 50arjun.dict has 2 attributes so length of it is 2. So total = 52.

Question 6.What would be the output of the following code snippets?print 4+9print “4+9”Answer:13 (addition), 49 (concatenation).

Question 7.Highlight the literals in the following programand also predict the output. Mention the types ofvariables in the program.

a=3 b='1' c=a-2 d=a-c e=“Kathy” f=‘went to party.’ g=‘with Sathy’ print a,g,e,f,a,g,“,”,d,g,“,”,c,g,“and his”,e,f

Answer:a, c,d = integerb, e,f,g = stringOutput: 3 with Sathy Kathy, went to party. 3 with Sathy, 2 with Sathy , 1 with Sathy and his Kathy, went to party.

Question 8.What is the result of 4+4/2+2?Answer:4 + (4/2) + 2 = 8.

Question 9.Write the output from the following code: [CBSE Text Book]

x= 10 y = 20 if (x>y): print x+y else: print x-y

Answer:– 10

Question 10.Write the output of the following code:print “Python is an \n interpreted \t Language”Answer:Python is an interpreted Language

Question 11.Write the output from the following code:

s = 0 for I in range(10,2,-2): s+=I print “sum= ",s

Answer:sum= 28

Question 12.Write the output from the following code: [CBSE TextBook]

n = 50 i = 5 s = 0 while i<n: s+ = i i+ = 10 print “i=”,i print “sum=”,s

Answer:

i= 15 i= 25 i= 35 i= 45 i= 55 sum= 125

Question 13.Write the output from the following code: [CBSE TextBook]

n = 50 i = 5 s = 0 while i<n: s+ = i i+ = 10 print “i=”,i print “sum=”,s

Answer:

i= 15 i= 25 i= 35 i= 45 i= 55 sum= 125

Question 14.Observe the following program and answer the question that follows:import randomx = 3N = random, randint (1, x)for 1 in range (N):print 1, ‘#’, 1 + 1a. What is the minimum and maximum number of times the loop will execute?b. Find out, which line of output(s) out of (i) to (iv) will not be expected from the program?i. 0#1ii. 1#2iii. 2#3iv. 3#4Answer:a. Minimum Number = 1Maximum number = 3b. Line iv is not expected to be a part of the output.

Question 15.Observe the following Python code carefully and obtain the output, which will appear on the screen after execution of it. [CBSE SQP 2016]

def Findoutput (): L = "earn" X = " " count = 1 for i in L: if i in ['a', 'e',' i', 'o', 'u']: x = x + 1. Swapcase () else: if (count % 2 ! = 0): x = x + str (len (L[:count])) else: x = x + 1 count = count + 1 print x Findoutput ()

Answer:EA3n

Question 16.Find and write the output of the following Python code:

Number = [9,18,27,36] for N in Numbers: print (N, "#", end = " ") print ()

Answer:

ElementStack of operatorsPostfix Expression1#001#(1#)(1#)2#(1#)(1#2#)1#(2#)(1#2#3#)2#(1#)1#3#(2#)1#2#(3#)1#2#3#

Question 17.What are the possible outcome(s) executed from the following code? Also,specify the maximum and import random. [CBSE Delhi 2016]

PICK=random.randint (0,3) CITY= ["DELHI", "MUMBAI", "CHENNAI", "KOLKATA"]; for I in CITY : for J in range (1, PICK) print (I, end = " ") Print ()

(i)(ii)DELHIDELHIDELHIMUMBAIMUMBAIDELHIMUMBAICHENNAICHENNAIDELHIMUMBAICEHNNAIKOLKATAKOLKATA(iii)(iv)DELHIDELHIMUMBAIMUMBAIMUMBAICHENNAIKOLKATAKOLKATAKOLKATAKOLKATA

Answer:Option (i) and (iii) are possible option (i) onlyPICKER maxval = 3 minval = 0

Question 18.Find and write the output of the following Python code : [CBSE Outside Delhi-2016]

Values = [10,20,30,40] for val in Values: for I in range (1, Val%9): print (I," * ", end= " ") print ()

Answer:

ElementStack of operatorsPostfix Expression1*001*(1.*)(1*)2*0(1*2*)1*(1,*)(1*2*3*)2*(2.*)1*3*01*2*(1.*)1*2*3*(2,* )(3,* )

Question 19.Write the output from the following code:

y = 2000 if (y%4==0): print “Leap Year” else: print “Not leap year”

Answer:Leap Year.

Question 20.What does the following print?

for i in range (1,10): for j in'range (1,10): print i * j, print

Answer:1 2 3 4 5 6 7 8 92 4 6 8 10 12 14 16 183 6 9 12 15 18 21 24 274 8 12 16 20 24 28 32 365 10 15 20 25 30 35 40 456 12 18 24 30 36 42 48 547 14 21 28 35 42 49 56 638 16 24 32 40 48 56 64 729 18 27 36 45 54 63 72 81

Question 21.What will be the output of the following statement? Also, justify the answer.

>> print ‘Radhsa’s dress is pretty’.

Answer:SyntaxError: invalid syntax.The single quote needs to be replaced by V to get the expected output.

Question 22.Give the output of the following statements :

>>> str=‘Honesty is the best policy’ >>> str.replace(‘o’,‘*’)

Answer:‘H*nesty is the best p*licy’.

Question 23.Give the output of the following statements :

>> str=‘Hello Python’ >>> str.istitle()

Answer:True.

Question 24.Give the output of the following statements:

>> str=‘Hello Python’ >>> print str.lstrip(“Hel”)

Answer:Hello Python

Question 25.Write the output for the following codes:

A={10:1000,20:2000,30:3000,40:4000,50:5000} print A.items() print A.keys() print A.values()

Answer:[(40,4000), (10,1000), (20,2000), (50,5000), (30,3000)] [40,10, 20, 50, 30] [4000,1000, 2000, 5000, 3000]

Question 26.Write the output from the following code:

t=(10,20,30,40,50) print len(t)

Answer:5

Question 27.Write the output from the following code:

t=(‘a’,‘b’,‘c’,‘A’,‘B’) print max(t) print min(t)

Answer:‘c’A’

Question 28.Find the output from the following code:

T=(10,30,2,50,5,6,100,65) print max(T) print min(T)

Answer:1002

Question 29.Write the output from the following code:

T1=(10,20,30,40,50) T2 =(10,20,30,40,50) T3 =(100,200,300) cmp(T1, T2) cmp(T2,T3) cmp(T3,T1)

Answer:0-11

Question 30.Write the output from the following code:

T1=(10,20,30,40,50) T2=(100,200,300) T3=T1+T2 print T3

Answer:(10,20,30,40,50,100,200,300)

Question 31.Find the output from the following code:

t=tuple() t = t +(‘Python’,) print t print len(t) t1=(10,20,30) print len(t1)

Answer:(‘Python’,)13

Question 32.Rewrite the following code in Python after remo¬ving all syntax error(s).Underline each correction done in the code.

for student in [Jaya, Priya, Gagan] If Student [0] = ‘S’: print (student)

Answer:for studednt in values [“Jaya”, “Priya”, “Gagan”]:if student [0] = = “S”print (student)

Question 33.Find and write the output of the following Python code:

Values = [11, 22, 33, 44] for V in Values: for NV in range (1, V%10): print (NV, V)

Answer:1, 112,223,334, 44

Question 34.What are the possible outcome(s) executed from the following code? Also, specify the maximum and minimum values that can be assigned to variable SEL.

import random SEL=random. randint (0, 3) ANIMAL = [“DEER”, “Monkey”, “COW”, “Kangaroo”]; for A in ANIMAL: for AAin range (1, SEL): print (A, end =“”) print ()

(i)(ii)(iii)(iv)DEERDEERDEERDEERDEERMONKEYMONKEYDELHIMONKEYMONKEYMONKEYMONKEYCOWCOWDELHIMONKEYCOWCOWKANGAROOKANGAROOKANGAROOKANGAROOKANGAROOKANGAROO

Answer:Maximum value of SEL is 3.The possible output is belowDEERMonkey MonkeyKangaroo Kangaroo KangarooThus (iv) is the correct option.

TOPIC-3Random Functions

Question 1.What are the possible outcome(s) executed from the following code ? Also specify the maximum and minimum values that can be assigned to variable PICKER. [CBSE Outside Delhi-2016]

import random PICKER = random randint (0, 3) COLOR = ["BLUE", "PINK", "GREEN", "RED"]: for I in COLOR : for J in range (1, PICKER): Print (I, end = " ") Print ()

(i)(ii)(iii) (iv)BLUEBLUEPINKSLUEBLUEPINKBLUEPINKPINKGREENPINKPINKGREENBLUEPINKGREENGREENREDGREENGREENREDBLUEPINKGREENREDREDRED

Answer:Option (i) and (iv) are possibleORoption (i) onlyPICKER maxval = 3 minval = 0

Question 2.What are the possible outcome(s) expected from the following python code? Also specifymaximum and minimum value, which we can have. [CBSE SQP 2015]

def main(): p = ‘MY PROGRAM’ i = 0 while p[i] != ‘R’: l = random.randint(0,3) + 5 print p[l],’-’, i += 1

(i) R – P – O – R –(ii) P – O – R – Y –(iii) O -R – A – G –(iv) A- G – R – M –Answer:Minimum value=5Maximum value=8So the only possible values are O, G, R, AOnly option (iii) is possible.

TOPIC-4Correcting The Errors

Question 1.Rewrite the following Python code after removing all syntax error(s). Underline the corrections done.[CBSE SQP 2015]

def main(): r = raw-input(‘enter any radius : ’) a = pi * math.pow(r,2) print “ Area = ” + a

Answer:

def main (): r = raw_input(‘enter any radius : ’) a = pi * math.pow(r,2) print “ Area = ”, a

Question 2.Rectify the error (if any) in the given statements.

>> str=“Hello Python” >>> str[6]=‘S’

Answer:

str[6] = ‘S’ is incorrect ‘str’ object does not support item assignment. str.replace(str[6],‘S’).

Question 3.Find the errors from the following code:T=[a,b,c]print TAnswer:NameError: name ‘a’ is not defined .T=[‘a’,‘b’,‘c’]

Question 4.Find the errors from the following code:for i in 1 to 100:print IAnswer:for i in range (1,100):print i

Question 5.Find the errors from the following code:

i=10 ; while [i<=n]: print i i+=10

Answer:

i=10 n=100 while (i<=n): print i i+=10

Question 6.Find the errors from the following code:

if (a>b) print a: else if (a<b) print b: else print “both are equal”

Answer:

if (a>b) // missing colon print a: else if (a<b) // missing colon // should be elif print b: else // missing colon print “both are equal"

Question 7.Find errors from the following codes:

c=dict() n=input(Enter total number) i=1 while i<=n: a=raw_input(“enter place”) b=raw_input(“enter number”) c[a]=b i=i+1 print “place”,“\t”,“number” for i in c: print i,��\t”,c[a[i]]

Answer:

c=dict() n=input(‘‘Enter total number”) i=1 while i<=n : a=raw_input(“enter place”) b=raw_inputf enter number”) c[a]=b i=i+1 print “place”,“\t”,“number” for i in c: print i,“\t”,c[i]

Question 8.Observe the following class definition and answer the question that follows : [CBSE SQP 2016]

class info: ips=0 def _str_(self): #Function 1 return "Welcome to the Info Systems" def _init_(Self): self. _ Sstemdate= " " self. SystemTime = " " def getinput (self): self . Systemdate = raw_input ("enter data") self , SystemTime = raw_Input ("enter data") Info, incrips () Estaiomethod # Statement 1 def incrips (): Info, ips, "times" I = Info () I. getinput () Print I. SystemTime Print I. _Systemdate # Statement 2

i. Write statement to invoke Function 1.ii. On Executing the above code, Statement 2 is giving an error explain.Answer:i. print Iii. The statement 2 is giving an error because _ Systemdate is a private variable and hence cannot to be printed outside the class.

TOPIC – 5Short Programs

Question 1.Write a program to calculate the area of a rectangle. The program should get the length and breadth ;values from the user and print the area.Answer:

length = input(“Enter length”) breadth = input(“Enter breadth”) print “Area of rectangle =”,length*breadth

Question 2.Write a program to calculate the roots of a quadratic equation.Answer:

import math a = input(“Enter co-efficient of x^2”) b = input(“Enter co-efficient of x”) c = inputfEnter constant term”) d = b*b - 4*a*c if d == 0: print “Roots are real and equal” root1 = root2 = -b / (2*a) elif d > 0: print “Roots are real and distinct” root1 = (- b + math.sqrt(d)) / (2*a) root2 = (-b - math.sqrt(d)) / (2*a) else: print “Roots are imaginary” print “Roots of the quadratic equation are”,root1,“and”,root2

Question 3.Write a program to input any number and to print all the factors of that number.Answer:

n = inputfEnter the number") for i in range(2,n): if n%i == 0: print i,“is a factor of’.n

Question 4.Write a program to input ,.any number and to check whether given number is Armstrong or not.(Armstrong 1,153,etc. 13 =1, 13+53 +33 =153)Answer:

n = inputfEnter the number”) savedn = n sum=0 while n > 0: a = n%10 sum = sum + a*a*a n = n/10 if savedn == sum: print savedn,“is an Armstrong Number” else: print savedn,”is not an Armstrong Number”

Question 5.Write a program to find all the prime numbers up to a given numberAnswer:

n = input("Enter the number”) i = 2 flag = 0 while (i < n): if (n%i)==0: flag = 1 print n,“is composite” break i = i+ 1 if flag ==0 : print n,“is prime”

Question 6.Write a program to convert decimal number to binary.Answer:

i=1 s=0 dec = int ( raw_input(“Enter the decimal to be converted:”)) while dec>0: rem=dec%2 s=s + (i*rem) dec=dec/2 i=i*10 print “The binary of the given number is:”,s raw_input()

Question 7.Write a program to convert binary to decimalAnswer:

binary = raw_input(“Enter the binary string”) decimal=0 for i in range(len(str(binary))): power=len (str (binary)) - (i+1) decimal+=int(str(binary)[i])*(2**power) print decimal

Question 8.Write a program to input two complex numbers and to find sum of the given complex numbers.Answer:

areal = input("Enter real part of first complex number”) aimg = input("Enter imaginary part of first complex number”) breal = input("Enter real part of second complex number”) bimg = input("Enter imaginary part of second complex number”) totreal = areal + breal totimg = aimg + bimg print “Sum of the complex numbers=",totreal, “+i”, totimg

Question 9.Write a program to input two complex numbers and to implement multiplication of the given complex numbers.Answer:

a = input("Enter real part of first complex number”) b = input("Enter imaginary part of first complex number”) c = input("Enter real part of second complex number”) d = input("Enter imaginary part of second complex number”) real= a*c - b*d img= a*d + b*c print “Product of the complex numbers=",real, “+i”,img

Question 10.Write a program to find the sum of all digits of the given number.Answer:

n = inputfEnter the number”) rev=0 while (n>0): a=n%10 sum = sum + a n=n/10 print “Sum of digits=”,sum

Question 11.Write a program to find the reverse of a number.Answer:

n = input("Enter the number”) rev=0 while (n>0): a=n%10 rev=(rev*10)+a n=n/10 print “Reversed number=”,rev

Question 12.Write a program to print the pyramid.12 23 3 34 4 4 45 5 5 5 5Answer:

for i in range(1,6): for j in range(1,i+1): print i, print

Question 13.Write a program to input username and password and to check whether the given username and password are correct or not.Answer:

import string usemame= raw_input(“Enter username”) password = raw_input(“Enter password”) if cmp(username.strip(),“XXX”)== 0: if cmp(password,”123”) == 0: print “Login successful” else: print “Password Incorrect” else: print “Username Incorrect”

Question 14.Write a generator function generatesq () that displays the squareroots of numbers from 100 to nwhere n is passed as an argument.Answer:

import math def generatesq (n) : for i in range (100, n) : yield (math, sqrt (i))

Question 15.Write a method in Python to find and display the prime number between 2 to n.Pass n as argument to the method.Answer:

def prime (N) : for a in range (2, N): for I in range (2, a): if N%i ==0 : break print a OR def prime (N): for a in range (2, N): for I in range (2, a) : if a%1= = 0 : break else : print a

Question 16.Write a program to input username and password and to check whether the given username and password are correct or not.Answer:

import string usemame= raw_input(“Enter username”) password = raw_input(“Enter password”) if cmp(usemame.strip(),“XXX”)== 0: if cmp(password,”123”) == 0: print “Login successful” else: print “Password Incorrect” else: print “Username Incorrect”

Question 17.Which string method is used to implement the following: [CBSE Text Book]

To count the number of characters in the string.

To change the first character of the string in capital letter.

To check whether given character is letter or a number.

To change lowercase to uppercase letter.

Change one character into another character.

Answer:

len(str)

str.title() or str.capitalize()

str.isalpha and str.isdigit()

lower(str[i])

str.replace(char, newchar)

Question 18.Write a program to input any string and to find the number of words in the string.Answer:

str = “Honesty is the best policy” words = str.split() print len(words)

Question 19.Write a program to input n numbers and to insert any number in a particular position.Answer:

n=input(“Enter no. of values") num=[] for i in range (n): number=input(“Enter the number") num.append(number) newno = input(“Enter the number to be inserted”) pos = input(“Enter position”) num.insert(newno,pos) print num

Question 20.Write a program to input n numbers and to search any number from the list.Answer:

n=input(“Enter no. of values”) num=[] flag=0 for i in range (n): number=input(“Enter the number”) num. append(number) search = input(“Enter number to be searched") for i in range(n): if num[i]==search: print search,“found at position”,i flag=1 if flag==0: print search, “not found in list”

Question 21.Write a program to search input any customer name and display customer phone numberif the customer name is exist in the list.Answer:

def printlist(s): i=0 for i in range(len(s)): print i,s[i] i = 0 phonenumbers = [‘9840012345’,‘9840011111’,’ 9845622222’,‘9850012345’,‘9884412345’] flag=0 number = raw_input(“Enter the phone number to be searched") number = number.strip() try: i = phonenumbers.index(number) if i >= 0: flag=1 except ValueError: pass if(flag <>0): print “\nphone number found in Phonebook at index”, i else: print'\iphonenumbernotfoundin phonebook” print “\nPHONEBOOK” printlist(phonenumbers)

Question 22.Write a program to input n numbers and to reverse the set of numbers without using functions.Answer:

n=input(“Enter no. of values”) num=[] flag=0 for i in range (n): number=input(“Enter the number”) num. append(number) j=n-1 for i in range(n): if i<=n/2: num[i],num[j] = num[j],num[i] j=j-1 else: break print num

Question 23.Find and write the output of the following Python code: [CBSE Complementry-2016]

class Client: def init (self, ID = 1, NM=”Noname”) # constructor self.CID = ID self. Name = NM def Allocate (self, changelD, Title) : self.CID = self.CID + Changeld self.Name = Title + self. Name def Display (self) : print (self. CID). "#”, self. Name) C1 = Client () C2 = Client (102) C3 = Client (205, ‘’Fedrick”) C1 . Display () C2 . Display () C3 . Display () C2 . Allocate (4, "Ms.”) C3 .Allocate (2, "Mr.”) C1. Allocate (1, "Mrs.”) C1. Display () C2 . Display () C3 . Display ()

Answer:

CID Name — Fedrick 102 Mr. Fedrick 205 Mrs. Fedrick — Mr. & Mrs. Fedrick

Question 24.What will be the output of the following Python code considering the following set of inputs?

MAYA Your 5 Apples Mine2 412 Also, explain the try and except used in the code. Count = 0 while True : try: Number=int (raw input ("Input a Number :")) break Except valueError : Count=Count + 2 # For later versions of python, raw_input # Should be consider as input

mehtods:– DenCal () # Method to calcualte Density as People/Area– Add () # Method to allow user to enter values Dcode, DName, People, Area and Call DenCal () Mehtod– View () # Method to display all the data members also display a message “”High Population”if the Density is more than 8000.Answer:Output is below2 Re Enter Number10 Re Enter Number5 Input = Number3 Input = numberTry and except are used for handling exception in the Pythan code.

Question 25.Write a method in Python and display the prime numbers between 2 to N. Pass as argument to the methods.Answer:

def prime (N) : for a in range (2, N) Prime=1 for I in range (2, a): if a%i= = 0 : Prime = 0 if Prime = = 1: print a OR def prime (N) : for a in range (2, N): for I in range (2, a) : if a%i = = 0: break else : print a OR Any other correct code performing the same

Long Answer Type Questions (6 marks)

Question 1.Aastha wnats to create a program that accepts a string and display the characters in the reversein the same line using a Stack. She has created the following code, help her by completing thedefinitions on the basis of requirements given below:[CBSE SQP 2016]

Class mystack : def inin (self): selfe. mystr= # Accept a string self.mylist= # Convert mystr to a list # Write code to display while removing element from the stack. def display (self) : : :

Answer:

class mystack : def _init_ (self) : self.myster= rawjnput ("Enter the string”) self.mylist = list (self.mystr) def display (self) : x = len (self. mylist) if (x > 0) : for i in range (x) : print self.mylist.pop (), else : print "Stack is empty”

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NCERT Class 12 Computer Science (Python) Solutions

NCERT Class 12 Computer Science (Python) Solutions :: CBSE Board

UNIT – I : OBJECT ORIENTED PROGRAMMING WITH PYTHON

Chapter 1 Review of Python

Chapter 2 Object Oriented Programming Concepts

UNIT – II : ADVANCE PROGRAMMING WITH PYTHON

Chapter 3 Lists Manipulation and Implementation

UNIT – III : DATABASES MANAGEMENT SYSTEM AND SQL

Chapter 4 Database Concepts

Chapter 5 Structured Query Language

UNIT – IV : BOOLEAN ALGEBRA

Chapter 6 Boolean Algebra

UNIT – V : NETWORKING & OPEN SOURCE SOFTWARE COMMUNICATION TECHNOLOGIES

Chapter 7 Networking and Open Source Concepts

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NCERT Class 12 Computer Science Chapter 7 Networking and Open Source Concepts

NCERT Class 12 Computer Science Python Solutions for Chapter 7 :: Networking and Open Source Concepts

TOPIC-1

Communication TechnologiesVery Short Answer Type Questions (1 Mark each)

Question 1:Identify the Domain name and URL from the following:https://ift.tt/2Rc5dG8Answer:Domain name – income.inURL – https://ift.tt/2Rc5dG8.

Question 3:Write two characterstics of Wi-Fi.Answer:

It is wireless network.

It is for short range.

Question 1:Which protocol is used to create a connection to a remote machine? Give any two advantages of using optical fibers.Answer:Two advantage of using optical fibers are:

Capable of extremely high-speed.

No electromagnetic interference.

Extremely low attending.

Question 6:Expand the following:

GSM

GPRS

Answer:

GSM: Global System for Mobile Commu-nication.

GPRS: General Packet Radio Service.

Question 7:What is the difference between packet and message switching ?Answer:

Question 9:Which type of network (out of LAN, PAN and MAN) is formed, when you connect two mobiles using Bluetooth to transfer a video?Answer:PAN

Question 12:Write two advantages of using an optical fibre cable over an Ethernet cable to connect two service stations, which are 200 m away from each other.Answer:Advantages of optical fibre:

Faster speed than ethernet

Lower attenuation

Question 14:Give one suitable example of each URL and Domain Name.Answer:URL: http://waltons.inDomain Name: @gmail.com

Question 16:What is the function of Modem?Answer:The function of modem is modulation and demo-dulation, means turn data into a format that can be transmitted via an audio link such as a phone line.

Question 18:Name any two components required for net-working.Answer:

Repeater

Routers

Question 20:Mention one advantage of star topology over bus topology in networking?Answer:Simple to add more computers to network.

Question 22:Differentiate between Bus and Star topology of network.Answer:

Question 29:Which of the following is not a unit for data transfer rate ?

bps

abps

gbps

kbps

Answer:(ii) abps

Question 30:Identify the type of topology from the following:

Each node is connected with the help of a single cable

Each node is connected with the help of independent cable with central switching.

Answer:

Bus topology

Star topology

Question 33:Which device is used to connect all computers inside a lab?Answer:Hub

Question 34:Which device is used to connect all computers to the internet using telephone wire?Answer:RJ – 45. It is an eight wired connectors used to connect computers on a LAN.

Short Answer Type Questions

Question 1:Write any two differences between twisted pair and co-axial pair cable.Answer:

Long Answer Type Questions

Jave Script

ASP

VB Script

JSP

Shortest distance between various locations:

Number of computers iinstalled at various locations are as follows:

Suggest the most appropriate location of the SERVER in the YHUB (out of the 4 locations), to get the best and effective connectivity. Justify your answer.

Suggest the best wired medium and draw the cable layout (location to location) to efficiently connect vari¬ous locations within the YHUB.

Which hardware device will you suggest to connect all the computers within each location of YHUB?

Which server/protocol will be most helpful to conduct live interaction of Experts from Head office and people at YHUB locations?

Answer:1.(a)OR(b) FTP or Telnet or TCPFTP OR Telnet OR TCP(c) Speed

Faster web browsing.

Faster file transferService –

Better video clarity

Better security

OR(Any other correct advantage can be considered)

(d) Makes web more interactive through online social media.Supports easy online information exchange.Interoperability on the internet.Video sharing possible in the websites.(e)

(f)

(g)(i) YTOWNJustification

Since it has the maximum number of computers.

It is closet to all other locatios.

(ii) Optical Fiber

(iii) Switch or Hub(iv) Video conferencing or VoIP or any other correct service/protocol.

Suggest the cable layout of connections between the buildings.

Suggest the most suitable place (i.e., building) to house the server of this school, provide a suitable reason.

Suggest the placement of the following devices with justification.

Repeater

Hub/Switch

Fiber optic cable

Microwave

Radiowave

Answer:

Server can be placed in the ADMIN building as it has the maxium number of computer.

Repeater can be placed between ADMINand SENIOR building as the distance is more than 110 m.

Radiowaves can be used in hilly regions as they can travel through obstacles.

Suggest a suitable Topology for networking the computers of all wings.

Name the most suitable wing where the Server should be installed. Justify your answer.

Suggest where all should Hub(s)/Switch(es) be placed in the network.

Which communication medium would you suggest to connect this school with its main branch in Delhi ?

Answer:

Server should be in Wing S as it has the maxi-mum number of computers. 1

All Wings need hub/switch as it has more thanone computer.

Since the distance is more, wireless transmission would be better. Radiowaves are reliable and can travel through obstacles.

Question 5:

Which out ot three type of networks LAN. MAN and WAN, is to be used when an institute connects computers of two adjacent computer laboratories ?

What is the difference between HTTP and FTP?

What is the major difference between Message Switching and Packet Switching in networking?

What is the basic difference between DNS and URL?

Give two applications of web 2.0.

Categories the following under client side and Server-Side script category?

JSP

ASP

VBScript

Jave Script

Answer:(i) LAN (The ange is upto one KM)(ii) (iv)(v) Application of web 2.0

web hosting

web browsing

web Indexing

web searching

(vi) Client side Script

JSP

Java ScriptServer Side Scripts

ASP

VB Script

What will be the most appropriate block, where TTC should plan to install their server?

Draw a block to cable layout to connect all the buildings in the most appropriate manner for efficient communication.

What will be the best possible connectivity out of the following, you will suggest to connect the new setup of offices in Bangalore with its London based office:

Satellite Link

Infrared

Ethernet Cable

Which of the following device will be suggested by you to connect each computer in each of the buildings:

Switch

Modem

Gateway

Answer:

Finance block because it has maximumnumber of computers.

Satellite link

Switch

Suggest the most suitable block in the Bengaluru Office Setup, to host the server.Give a suitable reason with your suggestion.

Suggest the cable layout among the various blocks within the Bengaluru Office Setup forconnecting the Blocks.

Suggest a suitable networking device to be installed in each of the blocks essentially required for connecting computers inside the blocks with fast and efficient connectivity.

Suggest the most suitable media to provide secure, fast and reliable data connectivity between Delhi Head Office and the Bengaluru Office Setup.

Answer:

Human Resources because it has maximum number of computers.

Switch 1

Satellite link

Suggest the most appropriate block, where RCI should plan to install the server.

Suggest the most appropriate block to block cable layout to connect all three blocks for efficient communication.

Which type of network out of the following is formed by connecting the computers of these three blocks?

LAN

MAN

WAN

Which wireless channel out of the following should be opted by RCI to connect to students from all over the world?

Infrared

Microwave

Satellite

Write two advantages of using open source software over proprietary software.

Which of the following crime(s) does not come under cybercrime?

Copying some important data from a computer without taking permission from the owner of-the data.

Stealing keyboard and mouse from a shop.

Getting into unknown person’s social networking account and start messaging on his behalf.

Answer:

Faculty Recording Block.

Star topology

LAN

Satellite connection

Advantages of open source over proprietary software:

Open source software’s source code is available, can be modified copied & distributed while propritary software can’t be change.

Open source is free while proprietary a paid.

Question 9:

Identify the type of topology on the basis ofthe following:

Since every node is directly connected to the server, a large amount of cable is needed which increases the installation cost of the network.

It has a single common data path connecting all the nodes.

Answer:

Star Topology

Bus Topology

(ii) Expand the following

VOIP

SMTP

Answer:

Voice Over Internet Protocol

Simple Mail Transder Protocol

(iii) Who is a hacker?

As a network expert, provide the best possible answer for the following queries:

Suggest a cable layout of connections between the buildings.

Suggest the most suitable place (i.e. building) to house the server of this organization.

Suggest the placement of the following device with justification:

Repeater (b) Hub/Switch

Suggest a system (hardware/software) to prevent unauthorized access to or from the network.

Answer:

Layout 1

The most suitable place / building to house the server of this organization would be building Research Lab, as this building contains the maximum number of computers.

Since the cabling distance between Accounts to Store is quite large, so a repeater would ideally be needed along their path to avoid loss of signals during the course of data flow in this route.

Firewall.

Question 10:

What is the difference between domain nameand IP address?

Write two advantages of using an optical fibre cable over an Ethernet cable to connect two service stations, which are 190 m away from each other.

Building to Building distances (in Mtrs.)

Suggest the most appropriate building, where EPG should plan to install the server.

Suggest the most appropriate building to building cable layout to connect all three buildings for efficient communication.

Which type of network out of the following is formed by connecting the computers of these three buildings?

LAN

MAN

WAN

Which wireless channel out of the following should be opted by EPG to connect to students of all over the world?

Infrared

Microwave

Satellite

Answer:

Domain Name is alphanumeric addressof a resource over network IP address is a Numeric Address of a resource in a Network.Example:Domain Name 1www.Gabsclasses.comIP Address102.112.0.153

Optical fibre Advantages:

Faster Communication.

Free from electrical & Noise interference.

(a) Faculty Studio Building(b) Bus Topology(c) LAN(d) Satellite

No village is more than 20 km away from the state capital.Imagine yourself as a computer consultant for this project and answer the following questions with justification:

Out of the following what kind of link should be provided to setup this network: Microwave link, Radio Link, Wired Link ?

What kind of network will be formed; LAN, MAN, or WAN ?

Many times doctors at village hospital will have to consult senior doctors at the base hospital. For this purpose, how should they contact them: using email, sms, telephone, or video conference ?

Answer:(a)

Radio Link

MAN

e-mail

Suggest the most suitable place (i.e., building) to house the server of this organization. Also give a reason to justify your suggested location.

Suggest a cable layout of connections between the buildings inside the campus.

Suggest the placement of the following devices with justification:

Repeater.

Switch.

The organization is planning to provide a high speed link with its head office situated in Mumbai using a wired connection. Which of the following cables will be most suitable for this job ?

Optical Fiber

Co-axial Cable

Ethernet Cable

Answer:

The most suitable place to install server is building “RED” because this building have maximum computer which reduce communication delay.

(b) In the layout a switch each, would be needed in all the buildings, to interconnect the group of cables from the different computers in each building.

(iv) Optical fiber

Suggest the most suitable place (i.e., block) to house the server of this organization. Also give a reason to justify your suggested location.

Suggest a cable layout of connections between the buildings inside the campus.

Suggest the placement of the following devices with justification:

Repeater

Switch

The organization is planning to provide a high speed link with its head office situated in the KOLKATA using a wired connection. Which of the following cable will be most suitable for this job?

Optical Fibre

Co-axial Cable

Ethernet Cable

Answer:

The most suitable place to install server is building “JAMUNA” because this building have maximum computer which reduce the communication delay.

Cable layout. (Bus topology).

Optical fiber

Suggest the most appropriate location of the SERVER in the Cluster (out of the 4 locations), to get the best and effective connectivity. Justify your answer.

Suggest the best wired medium and draw the cable layout (location to location) to efficiently connect various locations within the Cluster.

Which hardware device will you suggest to connect all the computers within each location of

Which service/protocol will be most helpful to conduct live interactions of Expersts from Head Office and peole at all locations of Cluster?

Answer:

Best location for the server is UVW-TOWN, because it is approximately equidistant from the village P, Q and R.

For connectivity between UVW-TOWN to head office is optic Fiber and to connect the villages, P, Q and R with server at UVW- TOWN is co-axial cable.

The villages R Q and R can be connected with server at UVW-TOWN by a Hub and the head office is connected by a Bus topology.

Between head office and UVWTOWNwe recommend for Bus topology, so HTTP protocol and other terminal can be connected by UDP or FTP protocols.

Distance between various Blocks :

Block A to Block C is 50 m

Block A to Block D is 100 m

Block B to Block C is 40 m

Block B to Block D is 70 m

Block C to Block D is 125 mNumber of Computers

Block A is 25

Block B is 50

Block C is 20

Block D is 120

Suggest a suitable network topology between the blocks.

Which is the most suitable block to house the server of this organization?

Suggest the placement of the following devices with justification

Repeater

Switch

The organization is planning to link the whole blocks to its marketing Office in Delhi. Since cable connection is not possible from Shimla, suggest a way to connect it with high speed.

Answer:

Suitable topology is bus topology.

The most suitable block for hosting server is BLOCK-D because this block has maximum number of computers.Mudra Publishing

TOPIC-2Network Security and Web ServiceVery Short Answer Type Questions(1 Mark each)

Question 2:Write any two examples of Server side Scripts.Answer:

ASP

PHP

Question 3:What is the difference between E-mail & chat?Answer:

Chat occurs in near real time, while E-mail doesn’t.

Chat is a 2-way communication which require the permission of both parties, while E-mail is a 1-way communication.

Question 4:Write names of any two popular open source software, which are used as operating systems.Answer:

Kernels

Unix

Linux

Question 6:Expand the following abbreviations :

HTTP

VOIP

Answer:

HTTP-Hyper Text Transfer Protocol.

VOIP-Voice Over Internet Protocol.

Question 8:What out of the following, will you use to have an audio-visual chat with an expert sitting in a far-away place to fix-up a technical issue ?

VoIP

FTP

Answer:(i) VoIP 1

Question 9:Name one server side scripting language and one client side scripting language.Answer:Client Side :

JAVASCRIPT

VBSCRIPTServer Side

ASP

JSP

Question 10:Which out of the following comes under cyber crime ?

Operating someone’s internet banking account, without his knowledge.

Stealing a keyboard from someone’s computer.

Working on someone’s Computer with his/ her permission.

Answer:(i) Operating someone’s internet banking account, without his knowledge.

Question 11:Name two proprietary software along with their application.Answer:

MS-Office – All office applications MS-Word, MS-Excel, MS-PowerPoint.

Visual Studio – Visual Basic, Visual C+ +software for application development.

Question 12:Out of the following, identify client side script (s) and server side script (s).

ASP

Javascript

VBScript

JSP

Answer:Server side scripting

ASP

JSPClient side scripting

Javascript

VBscript Vi

Question 14:Differentiate between XML and HTML.Answer:

Question 16:Which of the following is/are not a client side script:

VB Script

Java Script

ASP

PHP ?

Answer:(iii) ASP and(iv) PHP are not client side scripts.

Question 17:If someone has hacked your website, to whom you lodge the complaint ?Answer:The complaint has to be lodged with the police under IT Act.

Question 24:Give the full form of :

FOSS

HTTP

Answer:

FOSS : Free Open Source Software.

HTTP : Hyper Text Transfer Protocol.

Question 27:Write the full forms of the following:

GNU

XML

Answer:

GNU stands for “GNU’s Not Unix”

XML stands for “Extensible Markup Language”.

Question 28:Expand the following terminologies:

GSM

WLL (IMP)

Answer:

GSM: Global System for Mobile Communication

WLL: Wireless Local Loop.

Question 29:Name some cyber offences under the IT Act.Answer:

Tampering with computer source documents

Hacking.

Publishing of information which is obscenein electronic form.

Question 30:What are the three ways of protecting intellectual property ?Answer:

Patents

Copyrights

Trademark

Question 31:When a user browses a website, the web server sends a text file to the web browser. What is the name of this?Answer:Cookies.

Short Answer Type Questions

Question 1:Define the following:

Firewall

VoIE

Answer:

Firewall: A system designed to preventunauthorized access to or from a private network is called firewall, it can be implemented in both hardware and software or combination of both.

Question 2:Give the full form of the following terms.

XML

FLOSS

HTTP

FTP

Answer:

XML: Extensible Markup Language.

FLOSS: Free-Libre Open Source Software.

HTTP: Hyper Text Transfer Protocol.

FTP: File Transfer Protocol.

Question 4:Expand the following

GSM

GPRS.

Answer:

GSM: Global System for Mobile Communi-cation.

GPRS: General Packet Radio Service.

Question 5:Expand the following abbreviations :

HTTP

VOIP

Answer:

HTTP: Hyper Text Transfer Protocol.

VOIP: Voice Over Internet Protocol.

Question 6:Give the full form of :

FOSS

HTTP

Answer:

FOSS: Free Open Source Software.

HTTP: Hyper Text Transfer Protocol.

Question 7:Write the full forms of the following :

GNU

XML

Answer:

GNU: GNU’s Not Unix

XML: Xtensible Markup Language.

Question 8:Expand the following terminologies :

GSM

WLL

Answer:

GSM: Global System for Mobile Communi-cation

WLL: Wireless Local Loop.

Question 9:Give the full forms of the following terms :

CDMA

TDMA

FDMA

Answer:

CDMA: Code Division Multiple Access

TDMA: Time Division Multiple Access

FDMA: Frequency Division Multiple Access

Question 10:Expand the following abbreviations :

FTP

TCP

SMTP

VOIP

Answer:

FTP: File Transfer Protocol

TCP: Transmission Control Protocol.

SMTP: Simple Mail Transfer Protocol.

VOIP: Voice Over Internet Protocol

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