Fbise Notes-Computer Science | Networks and Communication | Class 8th Chapter no. 01

                  

 Networks and Communication   

             

  Multiple Choices

Q.1  Choose the correct option.

 i.  What does two or more computers connected together is called?

               A. GPS   

               B.   Network

 C. Modem 
 D. LAN

ii.  Which device is used to initiate the transmission of data?

              A.      Receiving Device   
              B.  Sending Device                 

             C.      Transmission Device 
             D. Communication Device

 iii.  Which device is used to send and receive data over telephone lines.

                

                   A.      WAN  
                   B.   Client                 

                  C.      Modem    
                  D.    Computer 

 iv.     The computer that uses the resources of server is called a?

                 A.         Switch      
                 B.   Server

                 C.         WAN 
                 D.  Client

  v.     How much area does a WAN cover?

                A.       A City              
                B.   A Continent

                C.       An Organization   
                D.   A Room 

 vi.     The cable that has insulated copper cable to carry data signals is?

                 A.        STP  
                 B.    Coaxial Cable

                 C.        UTP                           
                 D.   Fiber Optics 

vii.    What material is fiber optic cable made of?

                 A.        Glass Fibers            
                 B.    Copper Wires

                 C.        Insulator      
                 D.   Foil 

 viii.    Which technology is used for weather forecasting?

                

      A.       GPS               
      B.    Satellite Communication

     C.      Twisted Pair                    
     D.    Coaxial Cable

 ix.     How many times in a day a GPS satellite moves around the earth?

                 

                 A.        Twice   
                 B.   Four Times

                 C.        Thrice      
                D.  Five Times

 

x.       Cellular communication is based on?

                 A.    Cables       
                 B.   Cells     

                 C.    Insulator 
                 D.   Satellite                                          

        

               HAPPY NEW YEAR 2021

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Questions and Answers

Q.2 Define the following terms.

 i.    Network Interface Card

   A Network Interface Card is a computer hardware component that connects a computer to a network. The purpose of NIC is to prepare, send and control data on the network.

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 ii.   Transmission Medium

                    A transmission medium is a path used to send and receive data from the

              communication device. It may be wired or wireless.  

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  iii.    Physical Transmission Medium

                    A process to write a computer program using computer language is called

              programming.

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  iv.    Coaxial Cable

                   A coaxial cable is an insulated copper cable used to carry high frequency data

           signals such as voice, images, videos and text. It is used in cable tv transmission and

           in broad-band services like teleconferencing and net meeting.

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v.      Twisted Pair Cable

                  It consists of pairs of insulated copper wires twisted together. It is one of the

            oldest transmission medium.

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Q.3 Differentiate between the following.

Client	Server
The computer which uses the resources of a server is called client. The resources of a client can be shared according to requirements.	The computer which offers its resources and services to the other computer on a network. It manages user and computer accounts to provide secure access to its resources.

LAN	MAN
The network of computers confined in a building is called a LAN. Many business organizations are implementing LAN to obtain network benefits.	A MAN is an interconnection of multiple LANs within a city and sometimes in more than one city. A simple example of MAN is the cable TV network.

GPS	Bluetooth
The GPS is a satellite-based navigation system. It has 24 satellites, their base stations and GPS receivers all over the world.	Bluetooth is a short range wireless interconnection of electronic devices. It creates personal area network for users. Cell phones can be paired with headsets using Bluetooth.

                                           

Sender	Receiver
A sender is a device which is used to transmit the data over the network. It may be a computer, mobile phone.	A device is a device which accepts the data or information transmitted by sender over the network. A printer , a fax machine and a computer are examples  of receiver.

                                           

MAN	WAN
A MAN is an interconnection of multiple LANs within a city and sometimes in more than one city. A simple example of MAN is the cable TV network.	The term WAN is used in a computer network which spreads over a vast geographical area. PIA and internet are examples of WAN.

Q.4 Give brief answer of  the following.

Q.i What is computer Network?

Ans:           A computer network is defined as an interconnection of two or     more computers to facilitate communication and resource sharing. Common resources are printer, HDD, internet etc.

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Q.ii Define Network Components.

Ans: There are four basic components of a network:

a.      Sender

b.      Receiver

c.       Communication device

d.      Transmission medium  

Sender:

            A device which is used to transmit data over a network.

Receiver:

            A device which accepts data or information transmitted by sender.

Communication device:

                                    A device that encodes and transmits data over the physical or wireless medium is called communication device.

Transmission Medium:

                                    It is the path used to send and receive data from the communication device. It may be wire or wireless.

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Q.iii  What are advantages of LAN?

Ans:  Advantages of LAN

           

1.      Implementation is simple.

2.      Remote access and sharing.

3.      Low cast.

4.      Reliability and security.

5.      Fast communication and data transmission.

6.      Addition of new computers to network is easy.

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Q.iv  State some disadvantages of WAN

Ans:  Disadvantages of WAN

1.      Setting WAN is expensive and complicated.

2.      Security is real threat.

3.      Protection from hackers and viruses add more expenses.

4.      Maintenance of network is a full time job.

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Q.v  Write a short note on Bluetooth technology.

Ans:     Bluetooth Technology:

                                                It is a standard for short range wireless interconnection of electronics devices. It helps devices to connect to each other within a short range. Bluetooth creates personal area network (PAN) for its users. For example cell phone can be paired with headsets using Bluetooth. It is also workable with PC, laptops, printers, digital cameras, telephones and video game consoles.          

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  HAPPY NEW YEAR 2021

           

Q.4 Give detailed answer to the following questions.

Q.i What are the different types of computer Networks? Explain any two.

         

Ans: Types of Computer Networks:

                        There are three types of a computer network, these are;

a.      Local Area Network(LAN)

b.      Metropolitan Area Network (MAN)

c.       Wide Area Network (WAN)   

Local Area Network:

                        The network confined in a building is called LAN. Many business organizations are implementing it to obtain the following benefits;

1.      File and data sharing.

2.      Physical resources like printer, sharing.

3.      Application sharing.

4.      User authentication and management. 

Metropolitan Area Network:

                                    It is an interconnection of multiple LANs within a city or in more than one city. A simple example of MAN is cable TV network.

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Q.ii Write a detailed note on Dial-up Modem.

Ans: Dial-up Modem:     

            Dial-up Modem is a communication device that allows the user to connect computers using telephone line over the internet. The modem converts digital signal into analog which is known as modulation and then convert analog into digital, called demodulation. Hence the name modem. The limitation of modem are:

a.       Slow in speed

b.      If telephone is connected with internet, it cannot be used for phone calls

c.       Having signal distortion and noise

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Q.iii  Explain satellite communication in detail.

Ans:  Satellite Communication:       

                                    It is an artificial satellite in space for the purpose of telecommunication. It is launched by a rocket and placed in a specific orbit around the earth. It receives radio signals from one base station and transmits to the destination station situated thousands of miles away. There are hundreds of these satellites in operation around the world.

These are used for WAN communication, weather forecasting TV transmission, radio communication and internet access in GPS system.

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Q.iv What do you understand by GPS? Explain.

Ans:  Global Positioning System (GPS):

                                                            It is a satellite based navigation system. It has 24 satellites, their base stations and GPS receivers all over the world. It moves twice a day around the earth. It is used for finding paths, it helps the pilots in aviation to monitor their paths. It works in any weather conditions, anywhere in the world and 24 hours a day.

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Q.v  Explain the function of cellular communication.

Ans:  Cellular Communication:

                                                It is based on mobiles or cell phones as sending or receiving device. This device can be in a basic geographical service area, called a cell which is created by a network of radio wave transmitter. There are a number of transmitters to create cells. As mobile user travels from cell to cell, their conversation is handed over to the respective cell.

Key features of cellular networks are;

1. Increase capacity than a single larger transmitter.
2. Less power consumption at client side.
3. Larger coverage area than a single transmitter.

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QUIZ