Plus One

Students can Download Chapter 8 Computer Networks Questions and Answers, Plus One Computer Application Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Chapter Wise Questions Chapter 8 Computer Networks

Plus One Computer Application Computer Networks 1 Mark Questions and Answers

Question 1.
An interconnected collection of autonomous computers is called _______.
Answer:
Computer Networks

Question 2.
State true/false
A computer connected to a network is called work station.
Answer:
True

Question 3.
A work station is also called _______.
Answer:
Node

Question 4.
Which hardware is used to connect a work station to a network?
Answer:
Network Interface Card (NIC)

Question 5.
Rules and convention to transmit data on a network is called ______.
Answer:
Protocol.

Question 6.
In your computer lab sometimes you can see that cable from some computers are connected to a small box. What is it ?
Answer:
It is a Hub/Switch

Question 7.
The computers connected in your school lab is a ________ type network.
Answer:
Local Area Network

Question 8.
A Cable TV Network that spread over the city is a _________ type network.
Answer:
Metropolitan Area Network

Question 9.
Internet is a _____ type network.
Answer:
Wide Area Network

Question 10.
The school management is decided to connect computers in your HSS lab and high school lab located adjacent buildings. Which type of network is this?
Answer:
Local Area Network

Question 11.
A company decided to connect the computers of their branch located in another city away from 10 km. Name this network.
Answer:
metropolitan area network.

Question 12.
Geometrical arrangement of computers in a network is called _______.
Answer:
Topology

Question 13.
From the following select an ISP.
a) KSEB
b) KSRTC
c) BSNL
d) PWD
Answer:
c) BSNL

Question 14.
ISP means ______.
Answer:
Internet service provider

Question 15.
ISDN means _______.
Answer:
Integrated services digital network

Question 16.
State true/false.
In peer to peer configuration all the computers are with equal configuration.
Answer:
True

Question 17.
State true/false.
In client server configuration, a computer is powerful than others.
Answer:
True

Question 18.
Consider the following address.
http://www.nic.kerala.gov.in “in” is used to represent what ?
Answer:
“in” is used to represent the country “India”.

Question 19.
Which top level domain is used for non commercial organisation?
Answer:
org

Question 20.
Which geographical top level domain is used for the country “France”?
Answer:
fr

Question 21.
DNS stands for ________.
Answer:
Domain Name System

Question 22.
An IP address consists of ______ bits long.
(a) 4
(b) 16
(c) 32
(d) 64
Answer:
32 bits

Question 23.
An IP address consists of ______ bytes long.
(a) 4
(b) 16
(c) 32
(d) 64
Answer:
4 Bytes

Question 24.
From the following which media is using light rays for data transfer.
(a) Twisted pair cable
(b) Optical fibre
(c) Coanial cable
(d) Micro wave station
Answer:
b) Optical fibre

Question 25.
The wiring is not shared in a topology. Which is that topology.
Answer:
Star

Question 26.
______ is a combination of any two or more network topologies.
Answer:
Hybrid Topology

Question 27.
The nodes in a topology with two or more paths. Which topology is this?
Answer:
Mesh topology

Question 28.
Copying the signals from the earth to satellite is called ________.
Answer:
Uplink

Question 29.
Copying the signals from the satellite to earth is called _______.
Answer:
Downlink , Mesh topology

Question 30.
In very short distance networks, which communication media is used ?
Answer:
Twisted pair cables or coaxial cables.

Question 31.
In long distance networks, which communication medias are used?
Answer:
Optical fibre, microwave station, satellites, etc.

Question 32.
From the following which connector is used to connect UTP/STP twisted pair cable to a computer.
a) RJ-45
b) RS-1
c) CG-1
d) None of these.
Answer:
a) RJ-45

Question 33.
The cable media that use light to transmit data signals to very long distance is _______.
Answer:
Optical fibre cable

Question 34.
AM and FM radio broadcast and mobile phones make use of ______ medium for transmission.
Answer:
Radio waves

Question 35.
A short range communication technology that does not require line of sight between communicating device is ______.
Answer:
Wi-Fi

Question 36.
A communication system that is very expensive, but has a large coverage area when compared to other wireless communication system is ______.
Answer:
Satellite link

Question 37.
In which topology is every node connected to other nodes?
Answer:
Mesh topology

Question 38.
Any device which is directly connected to a network is generally known as ______.
Answer:
Node or Work station or Client or Terminal

Question 39.
In _____ topology all the nodes are connected to a main cable.
Answer:
Bus topology

Question 40
Write the full from of FTTH.
Answer:
Fibre To The Home

Question 41.
Which one of the following statements is TRUE in relation with Wi-MAX Internet connectivity?
a) make use of satellite connection
b) Uses cable connection
c) Uses laser beam for connection
d) Microwave is used for connectivity
Answer:
d) microwave is used for connectivity

Question 42.
Identify the type of LAN topology in which there are more than one path between nodes
a) Star
b) Ring
c) Mesh
d) Bus
Answer:
c) Mesh topology

Question 43.
a) To make data transfer faster, a switch stores two different addresses of all the devices connected to it. Which are they?
b) Name the device that can interconnect two different networks having different protocols.
Answer:
a) IP and MAC address
b) Gateway

Question 44.
a) Different networks with different protocols are connected by a device called….
i) Router
ii) Bridge
iii) Switch
iv) Gateway
b) Define protocol?
Answer:
iv) gateway
b) Protocol : The rules and conventions for transmitting data.

Plus One Computer Application Computer Networks 2 Marks Questions and Answers

Question 1.
Is it possible to connect all the computers to a network? Justify your answer.
Answer:
No. It is not possible to connect all the computers to a network. A computer, with a hardware called Network Interface Card (NIC), can only conect to a network.

Question 2.
Define Computer Networks?
Answer:
Two or more computers connected through a communication media that allows exchange of information between computers is called a Computer Network.
eg:- LAN, MAN, WAN

Question 3.
Do you heard about work station / Node. What is it?
Answer:
A personal computer connected to a network is called work station / Node.

Question 4.
Define a protocol.
Answer:
A protocol is the collection of rules and conventions used to exchange information between computer as a network.

Question 5.
Is the following a valid IP address?
258.1001.10.1.
Justify your answer?.
Answer:
No. It is not a valid IP address. An IP address has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255. Here 258 and 1001 are greater than 255. So it is not valid.

Question 6.
Mr. Dixon purchased a Laptop with bluetooth technology.
Answer:
It is a specification that allows mobile phones, computers and PDAS to be connected wirelessly over short distance.

Question 7.
Some Airport or college campus offers Wi-Fi facility. What is Wi-Fi?
Answer:
Wi-Fi means Wireless Fidelity. It is a wireless tech-nology. Some organisation offers Wi-Fi facility. Here we can connect internet wirelessly over short distance, using Wi-Fi enabled devices.

Question 8.
What is a protocol ?
Answer:
A protocol is a collection of rules and regulations to transmit data from one computer to another on a network. ”
eg:- http, ftp, TCP/IP, etc.

Question 9.
Explain Infrared waves in detail?
Answer:
These waves are used for transmitting data in short distance and its frequency range is 300 GHz to 400 GHz. Tv’s remote control, wireless mouse and intrusion detectors etc are the devices that used infrared.

Question 10.
Define resource sharing.
Answer:
Resource sharing means the computers on a network can share resources like software
(programs, data ) and hardware (printer,scanner, CD drive etc.).

Question 11.
Name two classification of communication channels between computers in a network.
Answer:
The two classification of communication channels are guided media and unguided media.

Question 12.
What is the use of a Repeater ?
Answer:
A Repeater is a device used to strengthen weak signals on the network and retransmits them to the destination.

Question 13.
Differentiate between router and Bridge.
Answer:
Bridge is a device used to link same type of networks while Router is similar to a bridge, but it can connect two networks with different protocols.

Question 14.
Categorise and classify the different types of network given below.
ATM network, Cable television network, Network within the school, Network at home using Bluetooth, Telephone network, Railway network
Answer:
PAN: Network at home using Bluetooth
LAN: Network within the school
MAN: Cable television network
WAN: ATM network, Telephone network, Railway network

Question 15.
What is PAN?
Answer:
PAN means Personal Area Network. It is used to connect devices situated in a small radius by using guided media(USB cable)or unguided media (Bluetooth, infra red, etc).

Plus One Computer Application Computer Networks 3 Marks Questions and Answers

Question 1.
What are the advantages of Networks?
OR
In a school lab all the 10 computers are connected to a network. We know that there is no need of 10 printers or 10 scanners why? Explain the advantages of Networks?
Answer:
The advantages of Networks are given below.
1) Resource sharing : All the computers in a network can share software (programs, data …..) and hardware (printer, scanner, CD drive etc ).
2) Reliability : If one computer fails, the other computer can perform the work without any delay. This is very important for banking air traffic control and other application.
3) Price Vs Performance : A main frame computer can be 10 times faster than a PC but it costs thousand times 9 PC. Therefore instead of a main frame 10 personal computers are used with less cost and same performance.
4) Communication Medium : It is a powerful communication medium. We can exchange information between computers in a network.
5) Scalable : This means, System performance can be increased by adding computers to a network.

Question 2.
Match the following.

Answer:
1) c
2) a
3) b
4) f
5) d
6) e

Question 3.
Your friend told you that a workstation and server are same. What is your opinion ? Is it true?
Answer:
No it is not true. A work station is a ordinary computer connected to a network. But a server is a powerful computer connected to a network. Its main aim is to serve the needs of workstation. Server is the master and workstations are the slaves.

Question 4.
Your friend told you that there are different types of servers. Do you agree with that ? Justify your answer?
Answer:
Yes, there are different types of servers, dedicated and non dedicated servers.
1) Dedicated Server : In large networks, a computer is reserved only for doing server function like sharing software and hardware resources and it is unavailable for running user applications and therefore increases system cost,
eg:- File server, Printer server etc.
2) Non dedicated Server : In smaller networks, a computer is doing the function of a server as well as it also act as a workstation.

Question 5.
Your friend asked you that a Hub or switch is better. What is your opinion ?
Answer:
A Hub is a device that receives data from a PC and transmit it to all other PC’s on the network. If two or more PC’s transmit data at the same time, there is a chance for collision. Hub is a cheap device and data transfer through a Hub is slow.
A switch is also a device and it transmits data to the right; recipient. There fore collision rate is low. A switch is faster but It is expensive.

Question 6.
ALAN is classified by their configuration. What are they?
Answer:
They are, peer to peer or client-server.
1) Peer to peer: In this configuration all the computers have equal priority. That means each computer can function as both a workstation and a server. There is no dedicated server.
2) Client-Server: In this configuration a computer is powerful which acts as a dedicated server and all others are clients (work stations). Server is the master and others are slaves.

Question 7.
Your friend told you that internet and intranet are same. Do you agree with that. Justify your answer.
Answer:
No. Internet and; intranet are not same. They are different.
Internet: It is a network of networks. It means that international network. We can transfer information between computers within nations very cheaply and speedily.
Intranet: A private network inside a company or organisation is called intranet.

Question 8.
Your friend decides to start an internet cafe in his shop. What are the requirements for this? Help him.
Answer:
1) Computer with a built in Modem or a facility to connect an external modem.
2) A telephone connection
3) An account with an ISP
4) Install respective software
eg:- Internet explorer or mozilla or netscape Navigator etc.

Question 9.
Considerthe following URLand explain each parts.
http://www.nic.kerala.gov.in / results.html.
Answer:
http:- http means hyper text transfer protocol. It is a protocol used to transfer hyper text.
www :- World Wide Web, With an email address
we can open our mail box from anywhere in the world.
nic.kerala :- It is a unique name. It is the official website name of National Informatic Centre
gov:- It is the top level domain. It means that it is a government organisation’s website.
resents the country, in is used for India.
results.html :- It represents the file name

Question 10.
Write any valid email and explain the working of an email.
Answer:
An example of an email id is jobi_cg @ rediffmail. com. Here jobi_cg is the user name, rediffmail is the website address and .com is the top level domain which identifies the types of the organisation. To send an email we require an email address. Some websites provide free email facility. To send an email first type the recipients address and type the message then click the send button.
The website’s server first check the email address is valid, if it is valid it will be sent otherwise the message will not ’ be sent and the sender will get an email that it could not deliver the message. This message will be received by the recipient’s server and will be delivered to recipient’s mail box. He can read it and it will remain in his mail box as long as he will be deleted.

Question 11.
Is it possible to give numeric address (IP address) to URL instead of string address of a website just like the following, http://210.212.239.70/
Answer:
Our Post Office has two addresses one string address (Irinjalakuda) and one numeric code (680121). Just like this the website has also two addresses a string address www.agker.cag.gov.in and a numeric address (htpt://210.212.239.70/).

Numeric Address (IP address) :- It has 4 parts one byte (8 bits) each separated by dots. One byte can represent a number in between 0 to 255. So we can use a number in between 0 to 255 separated by dots. It is a fastest method to access a website. To remember this number is not easy to humans. So a string address is used by humans,
eg:- http://203.127.54.1/.

String Address :- It uses a string to represent a website, it is familiar to the humans. The string ad-dress is mapped back to the numeric address using a Domain Name System (DNS). It may consists of 3 or 4 parts. The first part is www., the second part is website name, the third top level domain and the fourth geographical top level domain,
eg:-www.kerala.gov.in

Question 12.
Arun is in charge of networking the computers in your newly built computer lab.
a) Suggest any two options for communication media that can be used for connecting computers in your school lab.
b) Explain the structure and features of both.
Answer:
a) Twisted pair cables and coaxial cables.
b) Twisted Pair Wire : Two copper wires individually insulated, twisted around each other and covered by a PVC. There are two types of twisted pair wire. They are UTP and STP. It is very cheap and easy to install.
Coaxial Cable: A sturdy copper wire(conductor) is insulated by plastic. This is covered just like a mesh by a conductor , which in turn is enclosed in an protective plastic coating.
Compared to twisted pair wire it is more expensive, less flexible and more difficult to install. But it is more reliable and carry far higher data rates.

Question 13.
The computer uses digital signals and this signal is transmitted through telephone lines to computers at distant locations. Discuss how this is made possible.
Computer digital signals
Answer:
a) Modem
b) A Modem is a two in one device. That is it performs two functions. It is used to convert Digital signals to Analog, the process is Modulation(DAM) and the reverse process is converting Analog to Digital known as Demodulation (ADD).

Question 14.
Explain the structure of the television cable in your house. (3 Scores)
Answer:
Coaxial Cable: A sturdy copper wire(conductor) is insulated by plastic. This is covered just like a mesh by a conductor , which in turn is enclosed in an protective plastic coating.
Compared to twisted pair wire it is more expensive, less flexible and more difficult to install. But it is more reliable and carry far higher data rates. The various coaxial cables are RG-8,RG-9,RG-11,….

Question 15.
Answer the following questions from the list given below.
a) Device used to connect a network using TCP/IP protocol and a network using IPX/SPX protocol
b) Device that can convert a message from one code to another and transfer from one network to a network of another type.
(c) Device used to link two networks of the same type.
Answer:
a) Router
(b) Gateway
(c) Bridge

Question 16.
Find the most suitable match.

Answer:
i) www.keralapsc.org
ii) first page of a web site
ii) file with extension.htm
iv) www.yahoo.com

Question 17.
What do you mean by line of sight method of propagation.
OR
Why Micro wave station use tall towers instead of short one?
Answer:
Micro Wave signals can travel only in straight line. It cannot bend when the obstacles in between. There fore it uses tall towers instead of short one. The dish like antenna mounted on the top of the tower. Hence the two antennas must be in a straight line, able to look at each other without any obstacle in between.

Question 18.
Mr. Alvis took a photograph by using his mobile phone and he sends that photograph to his friend by using blue tooth. What is Blue tooth? Explain,
Answer:
This technology uses radio waves in the frequency * range of 2.402 GHz to 2.480 GHz. And transmit data in short distance. Mobile phones, Laptops, tablets etc use Bluetooth technology to transmit data. By using Bluetooth Dongle(a small device that can be buy from the shop) we can convert non Bluetooth PC into Bluetooth enabled and transmits data with data transmission rate of 3 Mbps onwards.

Question 19.
Differentiate Wi-Fi and Wi-Max in detail.
Answer:
Wi Fi(Wireless Fidelity) uses radio waves to transmit information across a network in a range 2,4 GHz to 5 GHz in short distance. Nowadays this technology is used to access internet in Laptops, Desktops, tablets, Mobile phones etc. But Wi MAX(Wireless Microwave Access) uses micro waves to transmit information across a network in a range 2 GHz to 11 GHz over very long distance

Question 20.
What is MAC address? What is the difference between a MAC address and an IP address?
Answer:
MAC means Media Access Control address. It is a unique 12 digit hexadecimal number(IMEI for mobile phones, it is a 15 digit decimal number) assigned to each NIC by its manufacturer. This address is known as MAC address and it is permanent., it is of the form. MM:MM: MM:SS:SS:SS.The first MM:MM:MM contains the ID number of the adapter company and the second SS:SS:SS represents the serial number assigned to the adapter by the company.
IP address means Internet Protocol address. It has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255(28=256 numbers). Each part is separated by dot. A total of 4*8=32 bits used. But nowadays 128 bits are used for IP address.

Question 21.
What is the limitation of microwave transmission? How is it eliminated?
Answer:
Micro Wave signals can travel only in straight line. It cannot bend when the obstacles in between. There fore it uses tall towers instead of short one. The dish like antenna mounted on the top of the tower. Hence the two antennas must be in a straight line; able to look at each other without any obstacle in between.

Question 22.
Explain the different types of networks,
Answer:
The networks are classified into the following.
i) Local Area Network (LAN)
This is used to connect computers in a single room, rooms within a building or buildings of one location by using twisted pair wire or coaxial cable. Here the computers can share Hardware and software. Data transfer rate is high and , error rate is less,
eg:- The computers connected in a school lab.
ii) Metropolitan Area Network (MAN)
A Metropolitan Area Network is a network spread over a city. For example a Cable TV network. MAN have lesser speed than LAN and the error rate is less. Here optical fibre cable is used.
iii) Wide Area Network (WAN)
This is used to connect computers over a large geographical area. It is a network of networks. Here the computers are connected using telephone lines or Micro Wave station or Satellites. Internet is an example for this. LAN and MAN are owned by a single organisation but WAN is owned by multiple organisation. The error rate in data transmission is high.

Question 23.
a) To make data transfer faster, a switch stores two
different addresses of all the devices connected to it. What are they?
b) There are 5 computers in your computer lab.
Write short notes on any three possible methods to interconnect these computers. Draw the diagram of each method.
Answer:
a) Identification of computers over a network : A computer gets a data packet on a network, it can identify the sender’s address easily. It is similar to our snails mail, each letter is stamped in sender’s post office as well as receiver’s post office.
1. Media Access Control(MAC) address : It is a unique 12 digit hexadecimal number(IMEI for mobile phones, it is a 15 digit decimal number) assigned to each NIC by its manufacturer. This address is known as MAC address and its permanent.
It is of the form. MM:MM:MM:SS:SS:SS.
The first MM:MM:MM contains the ID number of the adapter company and the second SS:SS:SS represents the serial number assigned to the adapter by the company.

2. Internet Protocol (IP) address : An IP address has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255(2°=256 numbers). Each part is separated by dot. A total of 4*8=32 bits used. But nowadays 128 bits are used for IP address.

b) Network topologies : Physical or logical arrangement of computers on a network is called structure or topology. It is the geometrical arrangement of computers in a network. The major topologies developed are star, bus, ring, tree and mesh.

1) Star Topology : A star topology has a server all other computers are connected to it. If computer A wants to transmit a message to computer B.
Then computer A first transmit the message to the server then the server retransmits the message to the computer B. That means all the messages are transmitted through the server, advantages are add or remove workstations to a star network is. easy and the failure of a workstation will not effect the other. The disadvantage is that if the server fails the entire network will fail.

2) Bus Topology : Here all the computers are attached to a single cable called bus. Here one computer transmits all other computers listen. Therefore it is called broadcast bus. The transmission from any station will travel in both the direction. The connected computers can hear the message and check whether it is for them or not.
Advantages are add or remove computer is very easy. It requires less cable length and the installation cost is less. Disadvantage is fault detection is very difficult because of no central computer.

3) Ring Topology : Here ail the computers are connected in the shape of a ring and it is a closed loop. Here also there is no central computer. Here a computer transmits a message, which is tagged along with its destination computer’s address. The message travels in one direction and each node check whether the message is for them. If not, it passes to the next node.
It requires only short cable length. If a single node fails, at least a portion of the network will fail. To add a node is very difficult.

4) Hybrid Topology : It is a combination of any two or more network topologies. Tree topology and mesh topology can be considered as hybrid topology.
a) Tree Topology : The structure of a tree topology is the shape of an inverted tree with a central node and branches as nodes. It is a variation of bus topology. The data transmission takes place in the way as in bus topology. The disadvantage is that if one node fails, the entire portion will fail.
b) Mesh Topology : In this topology each node is connected to more than one node. It is just like a mesh (net). There are multiple paths between computers. If one path fails, we can transmit data through another path.

Question 24.
ABC Ltd., required to connect their computers in their company without using wires. Suggest suitable medium to connect the computers. Explain.
Answer:
Unguided Media
1. Radio waves – It transmits data at different frequencies ranging from 3 KHz. to 300 GHz.
2. Microwaves – Microwave signals can travel in straight line if there is any obstacle in its path, it can’t bend. So it uses tall towers instead of short one.
3. Infrared waves – These waves are used for transmitting data in short distance and its frequency range is 300 GHz to 400 GHz.

Question 25.
It is needed to set up a PAN, interconnecting one tablet, two mobile phones and one laptop. Suggest a suitable communication technology and list its features for the following situations:
i) the devices are in a room at distance of 5 to 10 meters.
ii) the devices are in different rooms at a distance of 25 to 50 meters.
Answer:
i) Wireless communication technologies using radio waves
1. Bluetooth : This technology uses radio waves in the frequency range of 2.402 GHz to 2.480 GHz. And transmit data in short distance. Mobile phones, Laptops, tablets etc use Bluetooth technology to transmit data.
ii) Wi Fi(Wireless Fidelity) : It uses radio waves to transmit information across a network in a range 2.4 GHz to 5 GHz in short distance. Nowadays this technology is used to access internet in Laptops, Desktops, tablets, Mobile phones etc.

Question 26.
Computers and other communication devices can be connected a network using wireless technology.
a) A song is transferred from mobile phone to a laptop using this technology. Name the transmission medium used here.
b) Explain any other three communication media which use this technology
Answer:
a) Blue tooth or Radio waves
b) Wireless communication technologies using radio waves

1) Bluetooth : This technology uses radio waves in the frequency range of 2.402 GHz to 2.480 GHz. And transmit data in short distance. Mobile phones, Laptops, tablets etc use Bluetooth technology to transmit data.

2) Wi Fi(Wireless Fidelity) : It uses radio waves to transmit information across a network in a range 2.4 GHz to 5 GHz in short distance. Nowadays this technology is used to access internet in Laptops, Desktops, tablets, Mobile phones etc.

3) Wi MAX(Wireless Microwave Access) : It uses micro waves to transmit information across a network in a range 2 GHz to 11 GHz over very long distance.

4) Satellites : By using satellite we can communicate from any part of the world to any other. The ground stations are connected via the satellite. The data signals transmitted from earth to satellite (uplink) and from the satellite to the earth (downlink).

Question 27.
Find the correct match for each item in column A from columns B and C.

Answer:

Question 28.
Write notes on the following:
a) IP address
b) MAC address
c) Modem
Answer:
a) Internet Protocol (IP) address : An IP address has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255(28=256 numbers). Each part is separated by dot. A total of 4*8=32 bits used. But nowadays 128 bits are used for IP address.

b) Media Access Control(MAC) address: It is a unique 12 digit hexadecimal number(IMEI for mobile phones, it is a 15 digit decimal number) assigned to each NIC by its manufacturer. This address is known as MAC address.
It is of the form. MM:MM:MM:SS:SS:SS.

c) Modem : It is a device used to connect the computer to the internet. It converts digital signal into analog signal (modulation) and vice versa (De modulation)

Question 29.
Compare any three types of networks based on span of geographical area.
Answer:
Types of networks.
The networks are classified into the following based upon the amount of geographical area that covers.
i) Personal Area Network(PAN) : It is used to connect devices situated in a small radius by using guided media or unguided media
ii) Local Area Network (LAN): This is used to connect computers in a single room, rooms within a building or buildings of one location by using twisted pair wire or coaxial cable. Here the Computers can share Hardware and software. Data transfer rate is high and error rate is less,
eg:- The computers connected in a school lab.
iii) Metropolitan Area Network (MAN): A Metropolitan Area Network is a network spread over a city. For example a Cable TV network. MAN have lesser speed than LAN and the error rate is less. Here optical fiber cable is used.
iv) Wide Area Network (WAN): This is used to connect computers over a large geographical area. It is a network of networks. Here the computers are connected using telephone lines or Micro Wave station or Satellites. Internet is an example for this. LAN and MAN are owned by a single organization but WAN is owned by multiple organization. The error rate in data transmission is high.

Plus One Computer Application Computer Networks 5 Marks Questions and Answers

Question 1.
Explain the different network topologies,
Answer:
Physical or logical arrangement of computers of a network is called structure or topology. It is the geometrical arrangement of computers in a network. The major topologies developed are star, bus, ring, tree and mesh.

1) Star Topology : A star topology has a server all . other computers are connected to it. If computer A wants to transmit a message to computer B. . Then computer A first transmits the message to the server then the server retransmits the message to the computer B. That means all the messages are transmitted through the server. Advantages are add or remove workstations to a star network is easy and the failure of a workstation will not effect the other. The disadvantage is that if the server fails the entire network will fail.

2) Bus Topology : Here all the computers are attached to a single cable called bus. Here one computer transmits all other computers listen. Therefore it is called broadcast bus. The trans-mission from any station will travel in both the direction. The connected computers can hear the message and check whether it is for them or not.
Advantages are add or remove computer is very easy. It requires less cable length and the installation cost is less. Disadvantage is fault detection is very difficult because of no central computer.

3) Ring Topology : Here all the computers are connected in the shape of a ring and it is a closed loop. Here also there is no central computer. Here a computer transmits a message, which is tagged along with its destination computer’s address. The message travels in one direction and each node check whether the message is for them. IF not, it passes to the next node.It require only short cable length. If a single node fails, atleast a portion of the network will fail. To add a node is very difficult.

4) Hybrid Topology : It is a combination of any two or more network topologies. Tree topology and mesh topology can be considered as hybrid topology.
a) Tree Topology: The structure of a tree topology is the shape of an inverted tree with a central node and branches as nodes. It is a variation of bus topology. The data transmission takes place in the way as in bus topology. The disadvantage is that if one node fails, the entire portion will fail.
b) Mesh Topology : In this topology each node is connected to more than one node. It is just like a mesh (net). There are multiple paths between computers. If one path fails, we can transmit data through another path.

Question 2.
What are the different data communication equipments?
Answer:
1) Modem : A Modem is a two in one device. That is it performs two functions. It is used to convert Digital signals to Analog, the process is Modulation (DAM) and the reverse process is converting Ana-log to Digital known as Demodulation (ADD).

2) Multiplexer (Many to One): A multiplexer is a device that combines the inputs from different sources and produces one output. A demultiplexer does the reverse process.

3) Bridge : It is a device used to link two same type of networks.

4) Router : It is a device used to link two networks with different protocols.

5) Gateway : It is a device used to link two networks of different types. lt can convert a message from one code to another.

Question 3.
Explain the protocol TCP/IP
Answer:
TCP – (Transmission Control Protocol) is a connection oriented protocol. It is responsible for sending the data from one PC to another and also verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.

IP – is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte destination address (the IP number). The Internet authorities assign ranges of numbers to different organizations. The organizations assign groups of their numbers to departments. IP operates on gateway machines that move data from department to organization to region and then around the world.
In short TCP handle the flow control and error free packet delivery and IP provides basic addressing and data packets forwarding services.
Eg: 101.65.105.255

Question 4.
What is a protocol. Explain any four.
OR
Why protocol is necessary for communication? Ex-plain any two of them.
Answer:
A protocol is a collection of rules and regulations.to transfer data from one location to another. Transmission Control Protocol (TCP), which uses a set of rules to exchange messages with other Internet points at the information packet level. Internet Protocol (IP), which uses a set of rules to send and receive messages at the Internet address level. .
FTP – File Transfer Protocol which is used for transferring files between computers connected to local network or internet.
HTTP – is a protocol used for WWW for enabling the web browse to access web server and request HTML documents.

Students can Download Chapter 7 Control Statements Questions and Answers, Plus One Computer Application Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Chapter Wise Questions Chapter 7 Control Statements

Plus One Computer Application Control Statements 1 Mark Questions and Answers

Question 1.
An if statement contains another if statement completely. Then it is known as _______.
Answer:
Nested if

Question 2.
From the following which is not optional with switch statement.
a) break
b) default
c) case
d) none of these
Answer:
c) case.

Question 3.
To exit from a switch statement ____ is used
a) quit
b)exit
c) break
d) none of these
Answer:
c) break

Question 4.
From the following which statement is true for switch statement
a) switch is used to test the equality
b) switch is used to test relational or logical expression
c) switch can handle real numbers case data
d) none of these
Answer:
a) switch is used to test the equality

Question 5.
Sonet wants to execute a statement more than once. From the following which is exactly suitable.
a) if
b) loop
c) switch
d) if -else if ladder
Answer:
b) loop

Question 6.
Odd one out
a) for
b) if
c) switch
d) if else if ladder
Answer:
а) for
It is a loop the others are branching statement

Question 7.
a) for
b) if
c) while
d) do while
Answer:
b) if.
It is a branching statement and the others are loops

Question 8.
From the following which loop does the three things, initialisation, checking and updation.
a) while
b) do while
c) for
d) none of these
Answer:
c) for

Question 9.
Predict the output
for(i=1;i<=10;i++);
cout << i;
a) 10
b) 1 to 10
c) 11
d) none of these
Answer:
c) 11

Question 10.
From the following which is exit controlled loop
a) for
b) while
c) do while
d) None of these
Answer:
do while

Question 11.
_______ statement is used for unconditional jump from one location to another.
Answer:
goto

Question 12.
Sunitha wants to skip one iteration. From the fol-lowing which will help her?
a) continue
b) break
c) for
d) case
Answer:
a) continue

Question 13.
To terminate a program, from the following which is used ?
a) break
b) continue
c) end( )
d) exit( )
Answer:
exit( )

Question 14.
Which header file is needed to use exit( ) function in a program?
a) iostream
b) cstdlib
c) math
d) iomanip
Answer:
b) cstdlib

Question 15.
In while loop, the loop variable should be updated?
a) along with while statement
b) after the while statement
c) before the while statement
d) inside the body of while
Answer:
d) Inside the body of while

Question 16.
How many times the following loop will execute?
int S = 0, i =0;
do
{
S+= i;
i++;
}
while(i<5);
Answer:
5 times

Question 17.
a) _____ statement takes the program control out of the loop even though the test expression is true.
b) Consider the following code fragment. How many times will the character ‘ * ’ be printed on the screen?
for (1=0; i< 10; i =i+2);
{
cout << “*”;
}
Answer:
a) break or goto
b) Only one time because of semicolon(;) in the end of the for(i=0;i<10;i=i+2);

Question 18.
Which selection statement tests the value of a variable or an expression against a list of integers or character constants?
a) For
b) If
c) Switch
d) Conditional expression
Answer:
c) switch

Question 19.
How many times the following loop will execute?
int m = 2
do
{
cout << “Welcome”;
m++ ;
} while (m>10);
Answer:
Only one time.

Question 20.
statement takes the program control outside a loop even though the test expression is true.
Answer:
break

Question 21.
Read the following C++ statement
for (int n = 1; n<10; n+=2);
cout << n
Now, choose the correct output from the following options.
a) 1
b) 13579
c) 11
d) 10
Answer:
c) 11.
This is because of for statement is end with: (semi colon).
Here cout << n; executes only once.

Question 22.
______ search method is an example for ‘divide and conquer method’.
Answer:
goto

Question 23.
a) Name the type or loop which can be used to ensure that the body of the loop will surely be executed at least once.
b) Consider the code given below and predict the output;
for (int i=1; i<=9;i=i+2)
{
if (i==5) continue;
cout << i << ” ”
}
Answer:
a) do while loop(Exit controlled loop)
b) 1 3 7 9. It bypasses one iteration of the loop when i=5.

Plus One Computer Application Control Statements 2 Marks Questions and Answers

Question 1.
Your friend Arun asked you that is there any loop that will do three things, initialization, testing and updation. What is your answer. Explain ?
Answer:
Yes,
There is only one loop namely for loop that will do this three things. The other loops will do the . checking only, initialisation must be do before the 1 loop and updation must be inside the loop.
The syntax of for toop is given below
For(initialisation; testing; updation)
{
Body of the for loop;
}

Question 2.
While writing a program Geo uses while loop but forgets to update the loop variable. What will happen?
Answer:
The loop variable inside the while loop must be updated otherwise the loop will not be terminated The loop will be work infinitely.

Question 3.
Draw the flow chart of if statement.
Answer:

Question 4.
Draw the flow chart of if else statement .
Answer:

Question 5.
Write a while loop that display numbers from 500 to 550.
Answer:
int i=500
while (i<=550)
{
cout << i;
i=i+1;
}

Question 6.
Distinguish between exit(O) function and return statement.
Answer:
Both are used to terminate the program but both are different. Return is a keyword and exit(0) is a function.The difference is, we can use more than one exit(0) function but we can use only one return statement in a scope. To use exit(0), the header file cstdlib should be used.

Question 7.
Draw the flow chart of for loop.
Answer:

Question 8.
How many time the following for loop will execute? Justify.
for(i = 0; ; i ++)
{
if(i > 5)
cout << “continue”;
else
cout << “over”;
}
Answer:
Here the loop becomes infinite because the check condition is missing.

Question 9.
Predict the output.
#inctude<iostream.h>
int main( )
{
int a = 0;
start:
cout << endl << ++a;
if(a < 5)
goto start;
}
Answer:
1
2
3
4
5

Question 10.
for(int i=2, sum=0; i <= 20; i=i+2) sum += i;
Answer:
Rewrite the above code using while loop.
int i = 2;
sum=0;
while (i<=20)
{
sum +=i;
i = i +2;
}

Question 11.
Rewrite the following code using switch case statement.
if(day == 1)
cout << “Sunday”;
eise if(day == 2)
cout << “Monday”;
else if(day == 7)
cout << “Saturday”;
else
cout << “Wednesday”; (2 Scores)
Answer:
switch (day)
{
case 1:cout << “Sunday”;break;
case 2:cout << “Monday”;break;
case 7:cout << “Saturday”;break;
default:cout << “Wednesday”;
}

Question 12.
Pick the odd one out from the following. Give reason
1) a) for
b) while
c) do while
2) a) if
b) switch
c) for
Answer:
1) do ______ while It is an exit controlled loop while
others are entry controlled loop
2) for. It is a loop while others are branching statements.

Question 13.
State whether the following statements are True or False. In either case Justify your answer
a) Break statement is essential in switch
b) For loop is an entry controlled loop
c) Do… while loop is an entry controlled loop
d) Switch is a selection statement
Answer:
a) False. It is not essential in single case statement
b) True. Because it will first .check the condition. If it is true then only the body will be executed.
c) False. It is an exit controlled loop.
d) True.

Question 14.
Write the equivalent code for the following statement
R=(P<Q?P:Q)
Answer:
if(P<Q)
R=P;
else
R=Q;

Question 15.
Examine the following code snippet and find out the output? What will happen if the statement int ch; is replaced by char ch;
int ch;
for(ch=,A,;ch<-Z,;++ch)
cout << ch << ”;
Answer:
This code snippet will print 65,66,67 90. If
the statement int ch; is replaced by char ch; it prints A,B,C,………..,Z.

Question 16.
a) ______ is an entry control loop.
b) Explain the memory allocation for the following
int A[10] [10];
Answer:
a) while or for loop
b) To store On integer 4 bytes is used in Geany Editor
int A[10] [10]; .-> It needs 10*10*4 = 400 bytes7

Question 17.
Differentiate between break and continue statements in C++.
Answer:
break statement: It is used to skip over a part of the code i.e. we can premature exit from a loop such as while, do-while, for or switch.
Syntax:
while (expression)
{
if (condition)
break;
}
continue statement : It bypasses one iteration of the loop. That is it skips one iteration and continue the loop with next iteration value.
Syntax:
while (expression)
{
if (condition)
continue;
}

Plus One Computer Application Control Statements 3 Marks Questions and Answers

Question 1.
Compare if else and conditional operator?
Answer:
We can use conditional operator as an alternative of if-else statement. The conditional operator is a ternary operator.
The syntax of if- else
if (expression 1)
expression 2;
else
expression 3;
First expression 1 is evaluated if it is true expression 2 will be executed ptherwise expression 3 will be executed. Instead of this, we can be written as follows using conditional operator Expression 1 ? expression 2: expression3;

Question 2.
#include<iostream>
using namespace std;
int main( )
{
int n;
cout << “Enter a number in between 1-7”;
cin << n;
switch (n)
{
case 1: cout << “Sunday”;
break;
case 2: cout << “Monday”;
break;
case 3: cout << “Tuesday”;
break;
case 4: cout << “Wedesday”;
break;
case 5: cout << “Thursday”;
break;
case 6: cout << “Friday”;
break;
case 7: cout << “Saturday”;
break;
default : cout << “lnvalid”,
}
}
Rewrite the above code using if else if ladder.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n;
cout << “Enter a number in between 1-7:”;
cin << n;
if(n==1)
cout << “Sunday”;
else if(n=5=2)
cout << “Monday”;
else if(n==3)
cout << “Tuesday”;
else if(n==4)
cout << “Wedesday”;
else if(n==5)
cout << “Thursday”;
else if(n==6)
cout << “Friday”;
else if(n==7)
oout << “Saturday”; ‘
else
cout << “lnvalid”;
}

Question 3.
Rewrite the program following program using if else
#include<iostream>
using namespace std;
int main( )
{
int a,b,big;
cout << “Enter two integers”;
cin << a << b;
big=(a>b)?a:b;
cout << “Biggest number is ” << big << endl;
return 0;
}
Answer:
#include<iostream>
using namespace std;
intmain( )
{
int a,b,big;
clrscr( );
cout << “Enter two integers”;
cin << a << b;
if (a>b) big=a;
else big=b;
cout << “Biggest number is ” << big << endl;
return;
}

Question 4.
Consider the following code
#include<iostream>
using namespace std;
intmain( )
{ int mark;
clrscr( );
cout << “Enter a mark”; cin << mark;
if(mark>=75)
cout << “Distinction”;
else if (mark>=60) .
cout << “First class”;
else if (mark>=50)
cout << “Second class”;
else if (mark>=40) cout << “Passed”;
else
cout << “Failed”; .
}
Is it possible to rewrite the above program using switch statement? Distinguish between switch and if else if ladder.
Answer:
No. It is not possible to write the above code using switch statement. Following are the difference between switch and if else if ladder.
1) Switch can test only for equality but if can evaluate a relational or logical expression
2) If else is more versatile
3) If else can handle floating values but switch cannot .
4) If the test expression contains more variable if else is used
5) Testing a value against a set of constants switch is more efficient than if else.

Question 5.
Rewrite the following using nested switch construct
#include<iostream>
using namespace std;
int main( )
{
int a,b; .
cout << “Enter values for a and b”;
cin << a << b;
if(b==0)
cout << “Divide by zero error”;
else
if (a==0) .
cout << “The result is zero”;
else
cout << “The result is ” << (float)a/b;
}
Answer:
#include<iostream>
using namespace std;
int main( )
{
inta.b;
cout << “Enter values for a and b”;
cin << a << b;
switch (b)
{
case 0:cout << “Divide by zero error”;
break;
default:
switch(a)
{
case 0:cout << “The result is zero”;
break; .
default:
cout << “The result is” << (float)a/b;
}
}
}

Question 6.
Consider the following output and write down the code for the same.

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i j;
for(i=1;i<5;i++)
{
for(j=1;j<=i;j++)
cout << “*”;
cout << endl;
}
}

Question 7.
Consider the following output and write down the code for the same:

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i,j;
for(i=1;i<5;i++)
{
forG=1;j<=i;j++) cout << j << “”; cout << endl;
}
}

Question 8.
code for the same.

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i, j;
for(i=1;i<5;i++)
{
forG=1;j<=i;j++)
cout << i << ” “;
cout << endl;
}
}

Question 9.
Consider the following output and write down the code for the same.

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i, j, k=0;
for(i=1;i<5;i++)
{
for j=1;j<=i;j++)
cout << ++k << ” “;
cout << endl;
}
}

Question 10.
Consider the following output and write down the code for the same.

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i,j;
for(i=1;i<5;i++)
{
for(j=1;j<=i;j++)
cout << ++k << ” “;
cout << endl;
}
}

Question 11.
Consider the following output and write dowri the code for the same.

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i, j;
for(i=1 ;i<5;i++)
{
for(j=i ;j<=i;j++) cout << i*2 << ” “;
cout << endl;
}
}

Question 12.
Write a program to print the sum of first n natural numbers
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,i,sum=0;
cout << :”Enter a value for n”;
cin << n;
for(i=1;i<=n;i++)
{
sum=sum+i;
}
cout << “The sum of first ” << n << ” numbers is ” << sum;
}

Question 13.
Write a program to read a number and check whether it is palindrome or not.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,m,rem,rev=0;
cout << “Enter a number”;
cin << n;
m=n;
while(n)
{
rem=n%10;
rev=rev*10+rem;
n=n/10;
}
if(rev==m)
cout << “The number ” << m << ” is palindrome”;
else
cout << “The number ” << m << ” is not palindrome”;
}

Question 14.
Write a program to print the factorial of a number .
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,i;
longfact=1; .
cout << “Enter a number”;
cin << n;
for(i=1 ;i<=n;i++) fact=fact*i;
cout << “The factorial of “<;
<n << ” is ” << fact;
}

Question 15.
Write a program to print the Fibonacci series
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n, fib1=0,fib2=1,fib3;
cout << “Enter the limit”;
cin << n;
cout << “The fibonacci series is ”
if(n==1)
cout << fib1 << “,”;
else if(n==2)
cout << fib1 << “,” << fib2 << “,”;
else if (n>2)
{
cout << fib1 << “,” << fib2 << “,”;
fib3=fib1+fib2;
while(fib3<=n)
{
cout << fib3 << “,”;
fib1=fib2;
fib2=fib3; ,
fib3=fib1+fib2;
}
}
else
cout << “lnvalid”;
}

Question 16.
Write a program to read a number and check whether the given number is Armstrong or not
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,m,rem,cube=0;
cout << “Enter a number”;
cin >> n;
m=n;
while(n)
{
rem=n%10;
cube=cube+rem*rem*rem;
n=n/10;
}
if(cube == m)
cout << “The number ” << m << ” is Armstrong”;
else
cout << “The number ” << m << ” is not Armstrong”;
}

Question 17.
Write down the code for the following output using while loop.

Answer:
#include<iostream>
using namespace std;
int main( )
{
int i,j;
i=1
while(i<=4)
{
j=1;
while(j<=i)
{
cout << “*”;
j++;
}
i++;
cout << endl;
}
}

Question 18.
Distinguish between entry controlled loop and exit controlled loop.
Answer:
An entry controlled loop first checks the condition and execute(or enters in to) the body of loop only if it is true. But exit control loop first execute the body of the loop once even if the condition is false then check the condition. The for loop and while loop are entry, controlled loops but do- while loop is an exit controlled loop.

Question 19.
Write a program to find the largest of 3 numbers.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int a,b,c;
cout << “Enter three numbers”;
cin << a << b << c;
if (a > b && a > c)
cout << a << ” is large”;
else if (b>a && b>c) cout << b << ” is large”;
else
cout << c << ” is large”;
}

Question 20.
Check whether a given number is prime or not
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,i;
cout << “Enter a number”;
cin << n;
for(i=2;i<=n/2;i++)
{
if(n%i==0)
{
cout << n << “ is not a prime no.”;
return 0;
}
}
cout << n << “ is a prime”;
}

Question 21.
Write a program to print the prime numbers less than 100
Answer:
#include<iostream>
using namespace std;
int main( )
{
int i,j=4;
cout << “The prime numbers less than 100 is given below\n2,3,”;
while(j<=100)
{
for(i=2;i<=j/2;i++)
if(j%i==0)
break;
if(i==j/2+1)
cout << j << “,H;
j++;
}
}

Question 22.
Write a program to read number and display its factors.
Answer:
#include<iostream>
using namespace std;
int main( )
int n,i;
cout << “Enter a number greater than zero”;
cin << n;
cout << ‘The factors are”;
for(i=1;i<=n;i++)
if(n%i==0)
cout << i << “,”;
}

Question 23.
Write a program to print the Armstrong numbers less than 1000
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,i,rem,cube; for(i=1;i<=1000;i++)
{
n=i;
cpbe=0;
while(n)
{
rem=n%10;
cube=cube+rem*rem*rem;
n=n/10;
}
if(cube==i)
cout << i << “,”;
}
}

Question 24.
Char result;
float marks;
cin << marks;
if (marks >=50)
result = ‘P’;
else
result = ‘F’;
cout << result;
Rewrite the above code without using if statement.
Answer:
result=(marks>=50) ?’P’:’F’;

Question 25.
The output of a program is given below.
1
3
5
7
9
The sum is 25
Write a C++ program for obtaining the above output.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int sum=0,i;
for (i=*1; i<=9; i+=2)
{
cout << i << endl;
sum=sum+i;
}
cout << ‘The sum is” << sum;
}

Question 26.
Find out the error in syntax if any and correct it?
a) while (test condition);
{
}
b) do (condition)
{
}
while
c) switch(condition)
{
Case 1:
Case 2:
Case 3:
Case 4:
}
Answer:
a) No need of semi colon. The corrected loop is given below
While (test condition)
{
}
b) In do … while loop the while must be end with semicolon.
do (condition)
{
}
while;
c) switch contains expression instead of condition switch(expression)
{
Case 1:
Case 2:
Case 3:
Case 4:
}

Question 27.
Given the total mark of each student in SSLC examination. Write a C++ code fragment to find the grades.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int mark;
cout << “Enter total mark”;
cin << mark;
if (mark>100 || mark<0) cout << “lnvalid mark”;
else
{
If (mark>=90)
cout << “Your grade is A+”;
else if (mark>=80)
cout << “Your grade is A”;
else if (mark>=70)
cout << “Your grade is B+”;
else if (mark>=60)
cout << “Your grade is B”;
else if (mark>=50)
cout << “Your grade is C+”;
else if (mark>=40)
cout<£”Your grade is C”;
else if (mark>=30)
cout << “Your grade is D+”;
else
cout << “Your grade is D”;
}
}

Question 28.
You are given the heights of 3 students. Write the relevant code segment to find the maximum height?
Answer:
#include<iostream>
using namespace std;
int main( )
{
int h1,h2,h3,max;
cout << “Enter heightl cin << h1;
cout << “Enter height2:”;
cin << h2;
cout << “Enter height3:’f;
cin << h3;
if(h1>h2 && h1>h3)
max=h1;
else if(h2>h1 && h2>h3)
maxih2; .
else
max=h3;
cout << “The maximum height is “ << max;
}

Question 29.
Write the easiest code snippet for printing your name 1000 times. Explain
Answer:
#include<iostream>
using namespace std;
int main( )
{
int i;
char name[20];
cout << “Enter your name: cin << ‘name;
for(i=0;i<1000;i++)
cout << name << endl;
}

Question 30.
Given a code segment for(i=1; i<10; i++)
cout << i;
a) Rewrite the code using do while loop
b) What will be the output when i=0? Give reason.
Answer:
a) i=1;
do{
cout << i;
i++; .
}
while(i<10);
b) When i=0, it will execute one more time. ie. the for loop execute 9 times but here this loop executes 10 times.

Question 31.
Whenever a string is entered the inverse of that string is displayed( eg: if we enter-‘CAR’ the output is ‘RAC’). Write a suitable programme for the output.
Answer:
#include<cstdio>
#include<iostream>
#include<cstring>
using namespace std;
int main( )
{
int i, len;
char str[80];
puts(Enter a string :”);
gets(str);
len=strlen(str);
for(i=len-1;i>=0;i–)
putchar(str[i]).;
}

Question 32.
Qn. 32
Write a C++ program to display as follows

Answer:
#include<iostream>
using namespace std;
int main( )
{
char i,j;
for(i=’A’.;i<‘F’;i++)
{
for(j=’A’;j<=i;j++)
cout << j << “\t”;
cout << endl;
}
}
OR
#include<iostream>
using namespace std;
int main( )
{
int i,j;
for(i=65;i<70;i++)
{
‘ for(j=65;j<=i;j++)
cout << (char)j << “\t”;
cout << endl;
}
}

Question 33.
Write C++ program forgetting the following output.

OR
Consider the following C++ program and answer the following questions.
#include<iostream.h>
int main( )
{
int a, p=1;
for(a=1;a<=5;a+=2)
P = P*a;
cout << p;
}
a) Predict the output of the above code.
b) Rewrite the above program using while loop.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int i, j;
for(i=1;i<=4;i++)
{
for j=1;j<=i;j++)
cout << j << “\t”;
cout << “\n”; ‘
}
}
OR
a) The output is 15.
b) #include<iostream>
using namespace std;
int main( )
{
inta=1,p=1;
while(a<=5)
{
p=p*a;
a+=2;
}
cout << p;
}

Plus One Computer Application Control Statements 5 Marks Questions and Answers

Question 1.
We know that the execution of a program is sequential”. Is it possible to change this sequential manner and explain different jump statements in detail. .
Answer:
The execution of a program is sequential but we can change this sequential manner by using jump statements. The jump statements are

1. goto statement: By using goto we can transfer the control anywhere in the program without any condition. The syntax is goto label;
Eg.
#include<iostream>
using namespace std; int main( )
{
float a,b;
cout << “Enter 2 numbers”;
cin << a << b; . .
if(b==0)
goto end;
cout << “The quotient is ” << a/b;
return 0;
end:
cout << “Division by zero error”;
}

2. break statement: It is used to skip over a part of the code i.e. we can premature exit from a loop such as while, do-while, for or switch.
Syntax :
while (expression)
{
if (condition)
break;
}
Eg.
#include<iostream>
using namespace std;
main( )
{
int i=1;
while(i<10)
{
cout << i << endl;
if(i==5) break;
i++;
}
}
The output is
1
2
3
4
5

3. continue statement : lt bypasses one iteration of the loop.
Syntax :
while (expression)
{
if (condition)
break;
}
Eg:
#include<iostream>
using namespace std;
main( )
{
int i=0;
while(i<10)
{
i++; .
if(i==5) continue;
cout << i << endl;
}
}
The output is
1
2
3
4
5
6
7
8
9
10
4. exit(0) function: It is used to terminate the pro-gram. For this the header file cstdlib must be included.

Question 2.
Mr. X wants to get an output 9 when inputting 342 and he also wants to get 12 when inputting 651. Write the program and draw a suitable flowchart forX?
Answer:

#include<iostream>
using namespace std;
int main( )
{
int n,rem,sum=0;
cout << “Enter a number”;
cin << n;
while(n)
{
rem=n%10;
sum=sum+rem;
n= n /10;
}
cout << “The sum of digits is ” << sum;
}

Question 3.
Explain conditional statements in detail?

Answer:
1. Simple if:- The syntax is given below
if(expression)
statement;
or
if(expression)
{
Block of statements
}
First expression evaluates if it is true then only statement will be executed.
Eg. if (n>0)
cout << n << ” is positive”;

2. if else :-The syntax is given below,
if (expression)
statement 1;
else
statement 2;
or
if (expression)
{
statement block 1;
}
Else
{
statement block 2;
}
First expression evaluates if it is true statement block 1 will be executed otherwise statement block 2 will be executed. Only one block will be executed at a time so it is called branching statement.
Eg.
if (n>0)
cout << n << ” is positive”;
else
cout << n << ” is negative”;

3. if else if ladder:- The syntax will be given below
if (expression 1)
{
statement block 1;
else if (expression 2)
{
statement block 2;
}
else if (expression 3)
{
statement block 3;
}
else
{
statement block n;
}
Here first expression 1 will be evaluated if it is true only the statement block 1 will be executed otherwise expression 2 will be executed if it is true only the statement block2 will be executed and so on. If all the expression evaluated is false then only statement block n will be evaluated .
Eg.
If (mark>=90)
cout << “Your grade is A+”;
else if (mark>=80)
cout << “Your grade is A”;
else if (mark>=70)
cout << “Your grade is B+”;
else if (mark>=60)
cout << “Your grade is B”;
else if (mark>=50)
cout << “Your grade is C+”;
else if (mark>=40)
cout << “Your grade is C”;
else if (mark>=30)
cout << “Your grade is D+”;
else
cout << “Your grade is D”;

4. conditional operator:- It is a ternary operator and it is an alternative for if else construct.
The syntax is given below.
expression 1? expression 2: expression 3;
OR
expression 1? Value if true : value if false;
Here expression 1 will be evaluated if it true expression 2 will be executed otherwise expression 3 will be executed.
Eg.
n>0?cout << n << ” is positive”:cout << n << ” is negative”;

5. Switch It is a multiple branch statement. Its syntax is given below.
switch(expression)
{
case value: statements;break;
case value: statements;break;
case value: statemerits;break;
case value: statements;break;
case value: statements;break;
………….
default : statements;
}
First expression evaluated and selects the statements with matched case value.
Eg.
switch(n)
{
case 1: cout << “Sunday”;break;
case 2: cout << “Monday”;break;
case 3: cout << “Tuesday”;break;
case 4: cout << “Wedesday”;break;
case 5: cout << “Thursday”;break;
case 6: cout << “Friday”;break;
case 7: cout << “Saturday”;
break;
default : cout << “lnvalid”
}

Question 4.
Explain different loops in detail?
Answer:
1. For loop: The syntax of fbr loop is for(initialization; checking ; update loop variable)
{
Body of loop;
}
First part, initialization is executed once, then checking is carried out if it is true the body of the for loop is executed. Then loop variable is updated and again checking is carried out this process continues until the checking becomes false. It is an entry controlled loop.
Eg. for(i=1,j=1;i<=10;i++,j++)
cout << i << ” * ” << j << ” = ” << i*j;

2. While loop : It is also an entry controlled loop The syntax is given below
Loop variable initialised
while(expression)
{
Body of the loop;
Update loop variable;
}
Here the loop variable must be initialised out side the while loop. Then the expression is evaluated if it is true then only the body of the loop will be executed and the loop variable must be updated inside the body. The body of the loop will be executed until the expression becomes false.
Eg.
i=1;
j=1;
while(i<=10)
{
cout << i << ” * ” << j << ” = ” << i*j;
i++;
j++;
}

3. do While loop: It is an exit controlled loop. The syntax is given below do
{
Statements
}while(expression);
Here the body executes atleast once even if the condition is false. After executing the body it checks the expression if it false it quits the body otherwise the process will be continue.

Question 5.
Write a program to do the following:
a) Inputs the values for variables ‘n’ and’m’.
b) Prints the numbers between ‘1 ’ and ‘n’which are exactly divisible by ‘m’.
c) Checks whether the numbers divisible by ‘m’ are odd or even.
OR
Write a program using nested loop that inputs a number ‘n’ which generates an output as follows. Hint: if the value of ‘n’ is 5, the output will be as ‘n’.
—–
Answer:
b) #include<iostream.h>
#include<conio.h>
void main( )
{
clrscr( );
int i,n,m;
cout << “Enter values for n and m”;
cin << n << m;
for(i=1;i<=n;i++)
if(i%m==0)
cout << i << “,”;
getch( );
}

c) #include<iostneam.h>
#include<conio.h>
void main( )
{
clrScr( );
int i,n,m;
cout << “Enter values for n and m”;
cin << n << m;
for(i=1;i<=n;i++)
if(i%m==0)
{
cout << i << “\t”;
if(i%2==0)
cout << “even” << endl;
else
cout << “odd” << endl;
}
getch( ):
}
OR
#include<iostream.h>
#include<conio.h>
#include<string.h>//forstrlen( )
main( )
{
clrscr( );
int n,i,j;
cout << “enter a value for n:“;
cin >> n;
for(i=n;i>0;i–)
{
for(j – n;j > =i;j—) .
cout << j*j << “\t”;
cout << endl;
}
getch( );
}

Question 6.
Write a C++ program to display Fibonacci series.
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,fib1=0,Fib2=1,fib3;
cout << “Enter the limit”;
cin << n;
cout << “The fibonacci series is”;
if(n==1)
cout << fib1 << “,”;
else if(n==2)
cout << fib1 << “,” << fib2 << “,”;
else if (n>2)
{
cout << fib1 << “,” << fib2 << “,”;
fib3=fib1 +fib2; while(fib3<=n)
{
cout << fib3 << “,”;
fib1=fib2;
fib2=fib3;
fib3=fib1+fib2;
}
}
else
cout << “lnvalid”;
}

Question 7.
Write a C++ program to aocept an integer number and check whether it is an Armstrong number or not.
(Hint: Sum of the cubes of the digits of an Armstrong number is equal to that number itself)
OR
Write a C++ program to accept an integer number and print its reverse
(Hint: If 234 is given, the output must be 432).
Answer:
#include<iostream>
using namespace std;
int main( )
{
int n,m,rem,cube=0;
cout << “Enter a number”;
cin << n;
m=n;
while(n)
{
rem=n%10;
cube=cube+rem*rem*rem;
n=n/10;
}
if(cube==m)
cout << “The number ” << m << ” is Armstrong”;
else
cout << “The number ” << m << ” is not Armstrong”;
}
OR
(b) # include<iostream>
void main ( )
{
int n, rem, rev = 0;
cout << “Enter a number:”;
cin << n;
while (n)
{
rem = n%10;
rev = rev*10+rem;
n = n/10;
}
cout << “The reverse is” << rev;
}

Question 8.
Write a menu driven program which accepts 3 numbers and show options to find and display.
a) (i) the biggest number
(ii) the smallest number
(iii) the sun of the numbers
(iv) the product of the numbers
OR
b) Write a C++ program to check whether a number is palindrome or not.
Answer:
#include<iostream>
using namespace std;
int big (int n1, int n2, int n3)
{
if (n1>n2 && n1>n3)
return n1;
else if (n2>n1 && n2>n3)
return n2;
else
return n3;
}
int small (int n1, int n2; int n3)
{
if (n1<n2 && n1 < n3) return n1;
else if (n2<n1 && n2<n3)
return n2;
else
return n3;
}
int sum (int n1, int n2, int n3)
{
return (n1+n2+n3);
}
int prod (int n1, int n2, int n3)
{
return (n1*n2*n3);
}
void main ( )
{
\ intx,y,z,ch;
cout << “Enter 3 nos”;
cin << x << y << z;
cout << “Enter 1 for the biggest numebr”;
cout << “\n 2 for the smallest number”;
cout << “\n 3 for the sum of numbers”;
cout << “\n4 for the product of numbers”;
cout << “\n Enter your choice:”;
cin << ch;
switch (ch)
{
case 1 : cout << “The biggest number is” << big(x,y,z);
break; .
case 2 : cout << “The smallest number is” << small(x,y,z);
break;
case 3: cout << “The sum of number is” << big(x,y,z);
break;
case 4 : cout << “The product is” << prod(x,y,z);
break;
default: cout << “lnvalid choice”;
}
}
OR
b) #include<iostream>
using namespace std;
int main( )
{
int n,m,rem,rev=0;
cout << “Enter a number”;
cin << n;
m=n;
while(n)
{
rem=n%10;
rev=rev*10+rem;
n=n/10;
}
if(rev==m)
cout << “The number ” << m << ” is palindrome”;
else
cout << ”The number ” << m << ” is not palindrome”;
}

Question 9.
Answer any one question from (a) and (b).
a) Write a C++ program to display all leap years between 1000 and 2000 excluding all century years.
OR
b) Write a C++ program to find the sum of the first 10 numbers of Fibonacci series. (Fibonacci series is 0, 1, 1, 2, 3, 5, 8, 15 where 0 and,1 are the first two terms-and remaining terms are obtained by the sum of the two preceding terms.)
Answer:
a) # include < iostream>
using namespace std;
int main ( )
{
int i;
cout << “Leap years between 1000 and 2000 is given below \n”;
for (i= 1000; i<= 2000; i++)
{
if (i % 100 = = 0)
{
if (i % 400 == 0) cout << i << “, ”;
} else if (i % 4 = = 0) cout << i << “, ”;
}
}
OR
b) # include < iostream>
using namespace std;
void main ( )
{
int i, fib1 = 0, fib2 = 1, fib3, S ;
S = fib1+fib2;
for (i = 1; i <= 8; i + +)
{
fib3 = fib1 + fib2;
S = S + fib3;
fib1 = fib2; fib2 = fib3;
}
cout << “The sum of first 10 numbers of Fibonacii series is” << s;
}

Question 10.
Write a program to check whether the given number is palindrome or not.
OR
Write a program to print the leap years between 2000 and 3000.
(A century year is leap year only if it is divided by 400 and a noncentury year is leap year only if it is divided by 4.
Answer:
#include<iostream>
using namespace std;
int main( ) ‘{
int n,m,rem,rev=0; cout << “Enter a number”; cin << n;
m=n; while(n)
{
rem=n%10;
rev? rev*10+rem;
n=n/10;
}
if(rev==m)
cout << “The number “ << m << “ is palindrome”;
else
cout << “The number “ << m << “ is, not palindrome”; .
}
OR
#include<iostream>
using namespace std;
int main( )
{
int year;
for(year=2000;year<=3000;year++)
{
if(year%100==0)
{
if(year%400==0)
cout << year << endl;
}
else
{
if(year%4==0)
cout << year << endl;
}
}
}

Students can Download Chapter 8 Computer Networks Notes, Plus One Computer Application Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Notes Chapter 8 Computer Networks

Computer network: Two or more computers connected through a communication media that allows the exchange of information between computers is called a Computer Network.
Eg: Internet

Need for network
The advantages of Networks are given below.

1. Resource sharing: All the computers in a network can share software (programs, data ) and hardware (printer, scanner, CD drive, etc.).
2. Reliability: If one computer fails, the other computer can perform the work without any delay. This is very important for banking, air traffic control, and other application.
3. Price Vs Performance: A mainframe computer can be 10 times faster than a PC but it costs a thousand times a PC. Therefore instead of a mainframe 10 personal computers are used with less cost and the same performance.
4. Communication Medium: It is a powerful communication medium. We can exchange information between computers in a network.
5. Scalable: This means, System performance can be increased by adding computers to a network.

Terminologies
Bandwidth: The maximum amount of data that can be transmitted by the medium measured in Hertz.
Noise: It is the unwanted electrical or electromagnetic interferences that adversely affect the transmitted data signals.
Node: A computer or an I/O device connected to a network is called Node.

Data communication system
Communication is the exchange of information between two human beings. But data communication is the exchange of information between two computers(devices).
Message: It is the data/information to be transmitted from one computer to another
Sender: It is a computer or a device that sends data. It is also called source or transmitter
Receiver: It is a computer or a device that receives data.
Medium: It is the path through which a message transmitted from the sender to the receiver. There are two types Guided and Un Guided media. Protocol: The rules and conventions for transmitting data.

Communication Medium – There are two types guided and unguided.
Guided Media

1. Twisted Pair cable – 2 types unshielded twisted pair and shielded twisted pair. Two copper wires individually insulated and twisted around each other and put in a plastic cover.
2. Coaxial cable – A sturdy copper wire is insulated by plastic, it is covered just like a mesh by a conductor which is enclosed in a protective plastic coating. It is expensive, less flexible and more difficult to install. But it is more reliable and carry for higher data rates.
3. Optical fiber – These are made of glass fibers that are enclosed in a plastic jacket. It uses light instead of electrical signals. The light sources are LED or ILD.

Unguided Media

1. Radio waves – It transmits data at different frequencies ranging from 3 KHz. to 300 GHz.
2. Microwaves – Microwave signals can travel in straight line if there is any obstacle in its path, it can’t bend. So it uses tall towers instead of short one.
3. Infrared waves – These waves are used for transmitting data in short distance and its frequency range is 300 GHz to 400 GHz.

Wireless communication technologies using radio waves

1. Bluetooth: This technology uses radio waves in the frequency range of 2.402 GHz to 2.480 GHz. And transmit data in a short distance. Mobile phones, Laptops, tablets etc use Bluetooth technology to transmit data.
2. Wi-Fi(Wireless Fidelity): It uses radio waves to transmit information across a network in a range 2.4 GHz to 5 GHz in a short distance. Nowadays this technology is used to access internet in Laptops, Desktops, Tablets, Mobile phones etc.
3. Wi-MAX(Wireless Microwave Access): It uses micro waves to transmit information across a network in a range 2 GHz to 11 GHz over very long distance.
4. Satellites: By using satellites we can communicate from any part of the world to any other. The ground stations are connected via satellite. The data signals transmitted from earth to satellite (uplink) ahd from the satellite to the earth (downlink).

Data communication devices: It acts as an interface between computer and the communication channel

Network Interface Card (NIC): This device enables a computer to connect to a network and transmit information.

Hub: It is a small, simple and inexpensive device used to connect computers(devices) to a network. If a computer wants to transmit data to another computer. First it sends to the hub, the hub retransmits this data to all other computers. Each and every computer gets the data and check whether it is for them or not. It increases the network traffic and hence the transmission speed is low.

Switch: It is an expensive device used to connect computers(devices) to a network. Unlike a hub, switch transmit data not to all computers, it retransmits data only to the intended computer. So the traffic is less and speed is high

Repeater – It is a device used to strengthen weak signals on the network.

Bridge – It is a device used to link the same type of network.

Router – It is similar to a bridge, but it can connect two networks with different protocols.

Gateway – It is used to connect two different networks with different protocols.

Data terminal equipment: This device are used to control data flow to and from a computer

Modem – It is a device used to connect the computer to the internet. It converts the digital signal into an analog signal (modulation) and vice versa (Demodulation)

Multiplexer – It combines the inputs from different channels of a medium and produces one output.

Network topologies: Physical or logical arrangement of computers on a network is called structure or topology. It is the geometrical arrangement of computers in a network. The major topologies developed are star, bus, ring, tree, and mesh.

1. Star Topology: A star topology has a server all other computers are connected to it. If computer A wants to transmit a message to computer B. Then computer A first transmit the message to the server then the server retransmits the message to computer B. That means all the messages are transmitted through the server. Advantages are added or remove workstations to a star network is easy and the failure of a workstation will not affect the other. The disadvantage is that if the server fails the entire network will fail.

2. Bus Topology: Here all the computers are attached to a single cable called bus. Here one computer transmits all other computers listen. Therefore it is called a broadcast bus. The transmission from any station will travel in both the direction. The connected computers can hear the message and check whether it is for them or not.
Advantages are added or remove a computer is very easy. It requires less cable length and the installation cost is less. The disadvantage is fault detection is very difficult because of no central computer.

3. Ring Topology: Here all the computers are connected in the shape of a ring and it is a closed-loop. Here also there is no central computer. Here a computer transmits a message, which is tagged along with its destination computer’s address. The message travels in one direction and each node check whether the message is for them. If not, it passes to the next node.
It requires only short cable length. If a single node fails, at least a portion of the network will fail. To add a node is very difficult.

4. Hybrid Topology: It is a combination of any two or more network topologies. Tree topology and mesh topology can be considered as hybrid topologies.

a) Tree Topology: The structure of a tree topology is the shape of an inverted tree with a central node and branches as nodes. It is a variation of bus topology. The data transmission takes place in the way as in bus topology. The disadvantage is that if one node fails, the entire portion will fail.

b) Mesh Topology: In this topology, each node is connected to more than one node. It is just like a mesh (net). There are multiple paths between computers. If one path fails, we can transmit data through another path.

Types of networks
The networks are classified into the following based upon the amount of geographical area that covers.
i) Personal Area Network(PAN): It is used to connect devices situated in a small radius by using guided media or unguided media

ii) Local Area Network (LAN): This is used to connect computers in a single room, rooms within a building, or buildings of one location by using twisted-pair wire or coaxial cable. Here the computers can share hardware and software. The data transfer rate is high and the error rate is less.
eg: The computers connected in a school lab.

iii) Metropolitan Area Network (MAN): A Metropolitan Area Network is a network spread over a city. For example a Cable TV network. MAN has a lesser speed than LAN and the error rate is less. The here optical fiber cable is used.

iv) Wide Area Network (WAN): This is used to connect computers over a large geographical area. It is a network of networks.
Here the computers are connected using telephone lines or Micro Wave stations or Satellites. Internet js an example for this. LAN and MAN are. owned by a single organization but WAN is owned by multiple organizations. The error rate in data transmission js high. ,

Logical classification of networks
Peer to peer: In this configuration, all the computers have equal priority. That means each computer can function as both a client and a server. There is no dedicated server.

Client-Server: In this configuration, a computer is powerful which acts as a dedicated server and all others are clients (work stations). A Server fulfills the needs of the clients.

• File Server: A computer that stores and manages files for other devices on a network
• Web Server: A computer that handles the requests for web pages.
• Print Server: A computer that handles the print jobs from other computers on a network.
• Database Server: A computer that manages the database.

Network protocols
A protocol is a collection of rules and regulations to transfer data from one location to another. Transmission Control Protocol (TCP), which uses a set of rules to exchange messages with other Internet points at the information packet level. Internet Protocol (IP), which uses a set of rules to send and receive messages at the Internet address level

FTP – File Transfer Protocol which is used for transferring files between computers connected to local network or internet.
HTTP – is a protocol used for WWW for enabling the web browse to access web server and request HTML documents.
DNS (Domain Name System): When we type web sites address in the address bar , the browser determines the URL and asks the DNS for URLS corresponding IP address (Numeric address). The DNS returns the address to the browser.

Identification of computers over a network: A computer gets a data packet on a network, it can identify the sender’s address easily. It is similar to our snails mail, each letter is stamped in sender’s post office as well as receiver’s post office.

Media Access Control(MAC) address. It is a unique 12 digit hexadecimal number (IMEI for mobile phones, it is a 15 digit decimal number) assigned to each NIC by its manufacturer. This address is known as MAC address and its permanent.
It is of the form. MM:MM:MM:SS:SS:SS.
The first MM:MM:MM contains the ID number of the adapter company and the second SS:SS:SS represents the serial number assigned to the adapter by the company.

Internet Protocol (IP) address: An IP address has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255(28=256 numbers). Each part is separated by dot. A total of 4*8=32 bits used. But nowadays 128 bits are used for IP address.

Uniform Resource Locator(URL): Every resource on the internet has a unique URL. Mainly it has three parts
Eg: http://www.hscap.kerala.gov.in/index.html.
http: http means hyper text transfer protocol. It is a protocol used to transfer hyper text.
www: World Wide Web. With an email address we can open our mail box from anywhere in the world.
hscap.kerala: It is a unique name. It is the official website name of Single Window System
gov: It is the top-level domain. It means that it is a government organization’s website.
in: It is the geographical top-level domain. It represents the country, in is used for India.
index.html: It represents the file name.

TOP Level Domain Names

• .com – The site register for commercial purpose
• .edu – The site register for educational purpose
• .gov – The site register by Government agencies
• .mil – The site register for military services
• .net – The site register for network purpose
• .org – The site register by organizations

Country Specific Domain Names

• .in – India
• .au – Australia
• .ca – Canada
• .ch – China
• .jp – Japan
• .us – United States of America

Students can Download Chapter 7 Control Statements Notes, Plus One Computer Application Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Notes Chapter 7 Control Statements

These are classified into two decision making and iteration statements

Decision-making statements:
if statement:
Syntax: if (condition)
{
Statement block;
}
First, the condition is evaluated if it is true the statement block will be executed otherwise nothing will happen.

if… else statement:
Syntax: if (condition)
{
Statement block1;
}
Else
{
Statement block2;
}

Nested if
An if statement contains another if statement completely then it is called nested if.
if (condition 1)
{
if (condition 2)
{
Statement block;
}
}
The statement block will be executed only if both the conditions evaluated are true.

The else if ladder: The syntax will be given below
if (expression 1)
{
statement block 1;
}
else if (expression 2)
{
statement block 2;
}
else if (expression 3)
{
statement block 3;
}
else
{
statement block n;
}

Here firstly, expression 1 will be evaluated if it is true only the statement block1 will be executed otherwise expression 2 will be evaluated if it is true only the statement block 2 will be executed and so on. If all the expression evaluated is false then only statement block n will be executed

switch statement:
It is a multiple branch statement. Its syntax is given below.
switch(expression)
{
case value: statements;break;
case value: statements;break;
case value: statements;break;
case value: statements;break;
case value: statements;break;
…………..
default: statements;
}

First expression evaluated and selects the statements with matched case value. If all values are not matched the default statement will be executed.

Conditional operator: It is a ternary operator hence it needs three operands. The operator is ?:. Syntax: expression ? value if true : value if false. First evaluates the expression if it is true the second part will be executed otherwise the third part will be executed.

Iteration statements: If we have to execute a block of statements more than once then iteration statements are used.

while statement
It is an entry controlled loop. An entry controlled loop first checks the condition and execute(or enters in to) the body of loop only if it is true. The syntax is given below
Loop variable initialised
while(expression)
{
Body of the loop;
Update loop variable;
}

Here the loop variable must be initialised before the while loop. Then the expression is evaluated if it is true then only the body of the loop will be executed and the loop variable must be updated inside the body. The body of the loop will be executed until the expression becomes false.

for statement
The syntax of for loop is
for(initialization; checking ; update loop variable)
{
Body of loop;
}

First part, initialization is executed once, then checking is carried out if it is true the body of the for loop is executed. Then loop variable is updated and again checking is carried Out this process continues until the checking becomes false. It is an entry controlled loop.

do – while statement: It is an exit controlled loop. Exit control loop first execute the body of the loop once even if the condition is false then check the condition.
do
{
Statements
} while(expression);

Here the body executes at least once even if the condition is false. After executing the body it checks the expression if it false it quits the body otherwise the process will continue.

Students can Download Chapter 6 Introduction to Programming Notes, Plus One Computer Application Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Notes Chapter 6 Introduction to Programming

Structure of a C++ program
A typical C++ program would contain four sections as shown below.
Include files(Preprocessor directives)
Function declarations
Function definitions
Main function programs
Eg.
#include
using namespace std;
int sum(int x, int y)
{
return (x+y);
}
int main()
{
cout<<sum(2, 3);
}

Preprocessor directives: A C++ program starts with the preprocessor directive i.e., #include, #define, #undef, etc, are such a preprocessor directive. By using #inciude we can link the header files that are needed to use the functions. By using #define we can define some constants.
Eg. #define × 100. Here the value of x becomes 100 and cannot be changed in the program.
No semicolon is needed.

Header files:
header files: A header file is a pre-stored file that helps to use some operators and functions. To write C++ programs the header files are a must.
Following are the header files
iostream
iomanip
cstdio
cctype
cmath
cstring
The syntax for including a header file is as follows #include
Eg. #include

The main function: The main function is the first function which is invoked at the time of execution and the program ends within main(). The other functions are invoked from main().

Programming tips: The identifier name must be clear, precise, brief, and meaningful
Use clear and simple expressions.
Use comments wherever needed.
To give tips in between the program comments are used. A comment is not considered as part of the program and can not be executed. There are 2 types of comments single line and multiline.
Single line comment starts with //(2 slashes) but multi-line comment starts with /* and ends with */
indentation: Giving leading spaces to the statements is called indentation. It is a good programming practice.

Variable initialisation: Giving value to a variable at the time of declaration.
Eg: int age=16; Here the OS allocates 4 bytes memory for the variable age and it stores a value 16.

const – The access modifier: By using the keyword const we can create symbolic constants its value does not change during execution.
Eg: const int bp=100;

Type modifiers: With the help of type modifiers we can change the sign and range of data with the same size. The important modifiers are signed, unsigned, long and Short.

Shorthands in C++

Arithmetic assignment operators: It is faster. This is used with all the arithmetic operators as follows.

a) Increment operator(++): It is used for incrementing the content by one. ++x(pre increment) and x++ (post increment) both are equivalent to x = x+1.
b) decrement operator (–): It is used for decrementing the content by one. –x (pre decrement) and x– (post decrement) both are equivalent to x=x-1.

Prefix form: In this, the operator is placed before the operand and the operation is performed first then use the value.

Postfix form: In this, the operator is placed after the operand and the value of the variable is used first then the operation is performed.
Eg: Post increment a++
Here first use the value of ‘a’ and then change the value of ‘a’.
Eg: if a=10 then b=a++. After this statement b=10 and a=11 Pre increment ++a
Here first change the value of a and then use the value of a.
Eg: if a=10then b=++a. After this statement b=11 and a=11.

Precedence of operators: Consider a situation where an expression contains all the operators then the operation will be carried in the following order(priority)

Type conversion: Type conversions are of two types.
1) Implicit type conversion: This is performed by the C++ compiler internally. C++ converts all the lower sized data type to the highest sized operand. It is known as type promotion. Data types are arranged lower size to higher size is as follows.
unsigned int(2 bytes), int(4 bytes),long (4 bytes), unsigned long (4 bytes), float(4 bytes), double(8 bytes), long double(10 bytes)
2) Explicit type conversion: It is known as typecasting. This is done by the programmer. The syntax is given below.
(data type to be converted) expression
Eg. int x=10;
(float) x;
This expression converts the data type of the variable from integer to float.

Students can Download Chapter 5 Data Types and Operators Notes, Plus One Computer Application Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Notes Chapter 5 Data Types and Operators

Concepts of data types: The nature of data is different, data type specifies the nature of data we have to store.

C++ data types

Fundamental data types: It is also called built in data type. They are int, char, float, double and void
i) int data type: It is used to store whole numbers without fractional (decimal point) part. It can be either negative or positive. It consumes 4 bytes (32 bits) of memory. i.e. 2³² numbers. That is 231 negative numbers and 2³¹ positive numbers (0 is considered as +ve) So a total of 2³² numbers. We can store a number in between -2³¹ to + 2³¹ – 1.

ii) char data type: Any symbol from the keyboard, eg. ‘A’, ‘?’, ‘9’„…. It consumes one byte( 8 bits) of memory. It is internally treated as integers, i.e: 2⁸ = 256 characters. Each character is having a ASCII code, ‘a’ is having ASCII code 97 and zero is having ASCII code 48.

iii) float data type: It is used to store real numbers he. the numbers with decimal point. It uses 4 bytes(32 bits) of memory.
Eg. 67.89, 89.9 E-15.

iv) double data type: It is used to store very large real numbers. It uses 8 bytes(64 bits) of memory.

v) void data type: void means nothing. It is used to represent a function returns nothing.
User defined Data types: C++ allows programmers to define their own data type. They are Structure(struct), enumeration (enum), union, class, etc.
Derived data types: The data types derived from fundamental data types are called Derived data types. They are Arrays, pointers, functions, etc

Variables:
The named*memory locations are called variable. A variable has three important things

1. variable name: A variable should have a name
2. Memory address: Each and every byte of memory has an address. It is also called location (L) value
3. Content: The value stored in a variable is called content.lt is also called Read(R) value.

Operators: An operator is a symbol that performs an operation. The data on which operations are carried out are called operands. Following are the operators
1) Input(>>) and output(<<) operators are used to perform input and output operation. Eg. cin>>n;
cout<<n;

2) Arithmetic operators: It is a binary operator. It is used to perform addition(+), subtraction(-), division (/), multiplication(*) and modulus(%-gives the remainder) operations.
Eg. If x = 10 and y = 3 then

x/y = 3, because both operands are integer. To get the floating point result one of the operand must be float.

3) Relational operator: It is also a binary operator. It is used to perform comparison or relational operation between two values and it gives either true(1) or false(0). The operators are <, <=, >, >=, == (equality)and !=(not equal to)
Eg. If x = 10 and y = 3 then

4) Logical operators: Here AND(&&), OR(||) are binary operators and NOT (!) is a unary operator. It is used to combine relational operations and it gives either true(1) or false(0).
If x = 1 and y = 0 then

Both operands must be true to get a true value in the case of AND (&&) operation.
If x = 1 and y = 0 then

Either one of the operands must be true to get a true value in the case of OR(||) operation
If x = 1 and y = 0 then

5) Conditional operator: It is a ternary operator hence it needs three operands. The operator is?:. Syntax: expression ? value if true: value if false. First evaluates the expression if it is true the second part will be executed otherwise the third part will be executed.
Eg. If x = 10 and y = 3 then
x>y ? cout<>) operator is used to perform input operation.
Eg. cin>>n;

Output statements
output(<<) operator is used to perform output operation.
Eg. cout<<n; Cascading of I/O operations The multiple use of input or output operators in a single statement is called cascading of i/o operators. Eg: To take three numbers by using one statement is as follows cin>>x>>y>>z;
To print three numbers by using one statement is as follows
cout<<x<<y<<z;

Students can Download Chapter 4 Getting Started with C++ Notes, Plus One Computer Application Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Computer Application Notes Chapter 4 Getting Started with C++

It is developed by Bjarne Stroustrup. It is an extension of the C Language.

Character set: To study a language first we have to familiarize the character set. For example, to study the English language first we have to study the alphabet. Similarly here the character set includes letters(A to Z & a to z), digits(0 to 9), special characters(+, -, *, /, …..) white spaces(non printable) etc..

Token: It is the smallest individual unit similar to a word in English or Malayalam language. C++ has 5 tokens
1) Keywords: These are reserved words for the compiler. We can’t use it for any other purposes
Eg: float is used to declare variables to store numbers with a decimal point. We can’t use this for any other purpose

2) Identifier: These are user-defined words. Eg: variable name, function name, class name, object name, etc…

3) Literals (Constants): Its value does not change during execution
i) Integer literals: Whole numbers without fractional parts are known as integer literals, its value does not change during execution. There are 3 types of decimal, octal, and hexadecimal.
Eg. Fordecimal 100, 150, etc..
For octal 0100, 0240, etc..
For hexadecimal 0 × 100, 0 × 1A, etc

ii) Float literals: A number with fractional parts and its value does not change during execution is called floating-point literals.
Eg. 3.14157, 79.78, etc…

iii) Character literal: A valid C++ character enclosed in single quotes, its value does not change during execution.
Eg. ‘m’, ‘f ’ etc

iv) String literal: One or more characters enclosed in double-quotes is called string constant. A string is automatically appended by a null character(‘\0’)
Eg. “Mary’s”,’’ India”,etc

4) Punctuators: In English or Malayalam language punctuation marks are used to increase the readability but here it is used to separate the tokens.
Eg:{,},(,),…

5) Operators: These are symbols used to perform an operation (Arithmetic, relational, logical, etc…)

Integrated Development Environment(IDE): It is used for developing programs

• It helps to write as well as editing the program.
• It helps to compile the program and linking it to other (header files and other users) programs
• It helps to run the program

Turbo C++ IDE
Following is a C++ IDE

a) Opening the edit window
Method I: File → Click the menu item New
Method II: Press Alt and F simultaneously then press N

b) Saving the program:
Click File → Save or Press Function key F2 or Alt+F and then press S
Then give a file name and press ok.

c) Running/executing the program
Press Alt+R then press R OR Click Run → press R, OR Press Ctrl + F9

d) Viewing the output: Press Alt+F5

e) Closing Turbo C++ IDE
Click File → then press Quit menu Or Press Alt+X

Geany IDE

• Step 1: Take Geany Editor and type the program (source code)
• Step 2: Save the file with extension .cpp
• Step 3: Compile the program by Click the Compile Option
• Step 4: After successful compilation, Click the Build option
• Step 5: Then click on the Execute option

Students can Download Chapter 13 Organisation of Data Notes, Plus One Economics Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Economics Notes Chapter 13 Organisation of Data

Classification of Data
The groups or classes of classification can be done in various ways. The way you want to classify them would depend on your requirement. Likewise, the raw data could be classified in various ways depending on the purpose at hand.

1. Chronological Classification: They can be grouped according to time. Such a classification is known as a Chronological Classification. In such a classification, data are classified either in ascending or in descending order with reference to time such as years, quarters, months, weeks, etc. The variable ‘population’ is a Time Series as it depicts a series of values for different years.

2. Spatial Classification: In Spatial Classification the data are classified with reference to geographical locations such as countries, states, cities, districts, etc.

3. Qualitative Classification: Sometimes you come across characteristics that cannot be expressed quantitatively. Such characteristics are called Qualities or Attributes. For example, nationality, literacy, religion, gender, marital status etc. They cannot be measured. Yet these attributes can be classified on the basis of either the presence or the absence of a qualitative characteristic. Such a classification of data on attributes is called a qualitative classification.

4. Quantitative Classification: Characteristics like height, weight, age, income, marks of students, etc. are quantitative in nature. When the collected data of such characteristics are grouped into classes, the classification is a Quantitative Classification.

Continuous and discrete variable
A variable is that characteristic whose value is capable of changing from unit to unit. Variables can be continuous or discrete. A continuous variable is that which can take any value in a specified interval. Whereas discrete variables are those which can assume only certain values.

Exclusive and Inclusive Methods
Exclusive Method: Under the method, the upper-class limit is excluded but the lower class limit of a class is included in the interval. Thus an observation that is exactly equal to the upper-class limit, according to the method, would not be included in that class but would be included in the next class. On the other hand, if it were equal to the lower class limit then it would be included in that class.

Inclusive Method: There is another method of forming classes and it is known as the Inclusive Method of classification. In comparison to the exclusive method, the Inclusive Method does not exclude the upper-class limit in a class interval. It includes the upper class in a class. Thus both class limits are parts of the class interval.

Frequency Array
For a discrete variable, the classification of its data is known as a Frequency Array. Since a discrete variable takes values and not intermediate fractional values between two integral values, we have frequencies that correspond to each of its integral values.

Frequency Distribution
A frequency distribution is a comprehensive way to classify raw data of a quantitative variable. It shows how the different values of a variable are distributed in different classes along with their corresponding class frequencies.

Each class in a frequency distribution table is bounded by Class Limits. Class limits are the two ends of a class. The lowest value is called the Lower Class Limit and the highest value the Upper-Class Limit.

Class Interval or Class Width is the difference between the upper-class limit and the lower class limit. For class 60-70, the class interval is 10 (upper-class limit minus lower class limit).

The Class Midpoint or Class Mark is the middle value of a class. It lies halfway between the lower class limit and the upper-class limit of a class and can be ascertained in the following manner:

Class Midpoint or Class Mark = (Upper-Class Limit + Lower Class Limit)/2

The classmark or mid-value of each class is used to represent the class. Once raw data are grouped into classes, individual observations are not used in further calculations. Instead, the classmark is used. Frequency Curve is a Graphic representation of a frequency distribution.

Students can Download Chapter 12 Collection of Data Notes, Plus One Economics Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Economics Notes Chapter 12 Collection of Data

Sources of Data
Statistical data can be obtained from two sources. The enumerator may collect the data by conducting an inquiry or an investigation. Such data are called Primary Data, as they are based on first-hand information.
If the data have been collected and processed by some other agency, they are called Secondary Data. Generally, the published data are secondary data.

Methods of Collecting Primary Data
There are three basic ways of collecting data:

1. Personal Interviews
2. Mailing (questionnaire) Surveys
3. Telephone Interviews

1. Personal Interviews: This method is used when the researcher has access to all the members. The researcher conducts face to face interviews with the respondents. Personal contact is made between the respondent and the interviewer. The interviewer has the opportunity of explaining the study and answering any query of the respondents.

2. Mailing Questionnaire: When the data in a survey are collected by mail, the questionnaire is sent to each individual by mail with a request to complete and return it by a given date. The advantages of this method are that it is less expensive. It allows the researcher to have access to people in remote areas too, who might be difficult to reach in person or by telephone. It does not allow the influence of the respondents by the interviewer. It also permits the respondents to take sufficient time to give thoughtful answers to the questions.

3. Telephone Interviews: In a telephone interview, the investigator asks questions overthe telephone. The advantages of telephone interviews are that they are cheaper than personal interviews and can be conducted in a shorter time. They allow the researcher to assist the respondent by clarifying the questions. The telephone interview is better in the cases where the respondents are reluctant to answer certain questions in personal interviews.

Collection of Secondary Data
Secondary data are those which are available in published or unpublished records. Once a decision is taken to collect secondary data, the question of sources of data arises. There are two sources for the collection of secondary data, namely, published sources and unpublished sources.
Published Sources:

• Official publications of the central, state, and local governments.
• Official publications of international agencies like the United Nations Organization and its subsidiaries.
• Reports and publications of trade associations, chambers of commerce, banks, etc.
• Reports of committees and commissions.
• Reports published in technical trade journals.
• Reports submitted by researchers, economists, etc.

Unpublished Sources:

• Unpublished materials found with research institutes, trade associations, chamber of commerce, etc.

Census Survey and Sample Survey
Under census method, we collect information from each and every unit of population relating to the problem under investigation. On the other hand, the under-sample method, rather than collecting information about all the units of population, we collect information from a few selected items from the population.

Methods of Sampling
There are various methods of selecting samples from a population. These are called sampling techniques.
The two types of sampling techniques are random sampling and non-random sampling.

Random Sampling Methods
Random sampling is a technique of drawing a sample from the population in which each and every unit of the population has an equal chance of being included in the sample. It is further divided into simple random sampling and restricted random sampling.

a) Simple random sampling: In this method, the sample is taken from the population without making any division or classification of the population. Hence, every unit of the population has an equal chance of being selected in the sample. Simple random sampling may be done either by using lottery method or by Table of random numbers.

b) Restricted random sampling: Restricted random sampling is of mainly three types. Stratified sampling, systematic sampling and cluster sampling.

1. Stratified sampling: When the population is heterogeneous, stratified sampling method is used. Under this method the whole population is divided into various groups or strata of units, such that the units in each class possess similar characteristics. For example, suppose you are studying about the consumption pattern of students in your school. The population comprises the whole students studying in various standards of your school. A student studying in standard-5 and a student studying in standard-9 may have different consumption patterns. That is, for this characteristic, the population is heterogeneous. Hence, different standards can be selected as different groups or strata. Then sample is drawn from each stratum at random.

2. Systematic sampling: A systematic sampling is formed by selecting one at random and then selecting the rest at evenly spaced intervals until the sample size has been reached. Suppose that in the nature club of your school, there are 100 members and you want to make a core group of 10. First you number the 100 students of the club from 1 to 100. By lottery method or by random table method you select one student from the first ten. Let it be the 7th student. Then take an appropriate interval and select the rest 9 students. If the interval you had taken is 10, then the second student in the sample is the 17th student, the third student in the sample is the 27th student, etc.

3. Cluster sampling: This type of sampling is carried out in several stages. Suppose we are studying about the employment of households in Kerala. In the first stage, Kerala is divided into three or four zones. Then each zone is divided into districts. Then each district is divided into villages. From each district, sample of villages may be taken at random. From each selected village, households of required size are also taken at random. Since several stages involve in cluster sampling, it is also known as multi-stage sampling.

Non-Random Sampling
In this method of sampling the investigator himself makes the choice of sample from the population according to his own discretion which he thinks to be the best. Here, all the units in the population do not have equal chance of being selected in to the sample.

Sampling Errors and Non-Sampling Errors:
Sampling Errors
The purpose of the sample is to take an estimate of the population. Sam^g error refers to the differences between the sample estimate and the actual value of a characteristic of the population. It is the error that occurs when you make an observation from the sample taken from the population. Thus, the difference between the actual value of a parameter of the population and its estimate is the sampling error.

Non-Sampling Errors
Non-sampling errors are more serious than sampling errors because a sampling error can be minimized. But errors due to mistakes while framing tables and data entry will affect the final result. They are non-sampling errors.

Students can Download Chapter 11 Introduction Notes, Plus One Economics Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus One Economics Notes Chapter 11 Introduction

Statistics
Statistics deals with the collection, classification analysis, and interpretation of numerical data. In our daily language, the word ‘Statistics’ is used in two distinct senses: singular and plural. In the plural sense, ‘statistics’ means ‘numerical facts systematically collected’ as described by the Oxford Dictionary. Thus, the simple meaning of statistics in the plural sense is data.

Functions of Statistics

• It simplifies the complexity of data: Complex numerical data are simplified through statistical methods.
• It reduces the bulk data: Huge data can be reduced to a few figures and thus, easily understandable.
• It adds precision in thinking: It actually sharpens one’s thinking faculty.
• It helps comparison of different sets of figures: e.g. import and export of two countries can be compared.
• It indicates trends and tendencies: Helps in making future plans.
• It helps in studying relationships between different factors: With the help of statistical methods, one can study the relation between two or more variables.
• It guides in the formulation of policies and helps in planning: Planning and policies of the government are based on statistical data.

Limitations of Statistics
The limitations of statistics are given below.

• Statistical laws are true only on average.
• Statistics can be misused.
• Statistics deals only with quantitative data.
• Statistical results lack mathematical accuracy.
• Statistical facts are collected for a pre-determined purpose.