Unit – II – Test -1
1. ARPANET stands for _______.
A.Advanced Recheck Projects Agency Internet B.Advanced Recheck Projects Agency Network
C.Advanced Research Projects Agency Network D.Advanced Research Projects Agency Internet
Advanced Research Projects Agency Network (ARPANET)
2. In which of the following switching methods, the message is divided into small packets?
A. Message switching `B. Packet switching C. Circuit switching D. None of these
Packet switching
3. Which of the following switch methods creates a point-to-point physical connection between two or more computers?
A. Message switching B. Packet switching C. Circuit switching D. None of these
Circuit switching
4. A Computer Network:
A. Is a collection of hardware components and computers? B. Is interconnected by communication channels
C. Allows sharing of resources and information D. All of the above
Allows sharing of resources and information
5. Two devices are in network if A.
A process in one device is able to exchange information with a process in another device
B. A process is running on both devices
C. The processes running of different devices are of same type
D. None of the above.
they must be able to exchange information with each other
6. What is a network? What are its goals and applications?
7. Briefly explain how Internet evolved.
8. Write a short note on ARPAnet.
9. How does Internet work?
10. Write a short note on Interspace.
11. How is circuit switching different from message switching?
12. How does transmission take place across networks?
13. What are communication channels? Discuss various communication channels available for networks.
14. What is bandwidth? How it measured?
15. What do you understand by data transfer rates?
What is a network? What are its goals and applications?
A collection of interconnected computers is called network.
Or
A network is an interconnected collection of autonomous computers that can share and exchange information.
Application: -
(i) Resource Sharing: - Through a network, data, software and hardware resources can be shared irrespective of the physical
location of the resources and the user.
(ii) Reliability: - A file can have its copies on two or more computers of the network, so if one of them is unavailable, the other
copies could be used. That makes a network more reliable.
(iii) Reduced Costs: - Since resources can be shared, it greatly reduces the costs.
(iv) Fast communication. With network, it is possible to exchange information at very fast speed.
2. Briefly explain how Internet evolved.
The Internet is a worldwide network of computer networks that evolved from the first network ARPAnet (Advanced Research
Projects Agency network). The Internet is made up of many networks each run by a different company and interconnected at
peering points. The common use of Internet standards allows users connected to one network to communicate with users on
another network.
3. Q. Write a short note on ARPAnet.
The first computer network was jointly designed by the Advanced Research Projects Agency (ARPA) and Department of
Defense (DoD) of United States in 1969 and was called ARPANET. It was an experimental project, which connected a few
computers from some of the reputed universities of USA and DoD. ARPANENT allowed access to computer resource sharing
projects. This ARPANET was handed over to Defense Communication Agency (DCA) for further development.
4. How does Internet work?
Working of Internet:-
(i) At the source computer, the message or the file/document to be sent to another computer is firstly divided into very small parts
called Packets. A packet generally contains some information.
(ii) Each packet is given a number serial wise e.g., 1, 2, 3.
(iii) All these packets are then sent to the address of destination computer.
(iv) The destination computer receives the packets in random manner. (It may even receive packet 10 before packet 1 arrives). If a
packet is garbled or lost, it is demanded again.
(v) The packets are reassembled in the order of their number and the original message/file/document is obtained.
5.Write a short note on Interspace.
Interspace is a client/server software program that allows multiple users to communicate online with real- time audio, video and
text chat in dynamic 3D environments.
6. How is circuit switching different from message switching?
In Circuit Switching:-
• The complete physical connection between two computers is established and then data are transmitted from the source computer
to the destination computer.
• The important property of this switching technique is to setup an end-to-end path (connection) between computers before any
data can be sent.
While in Message Switching:-
In this form of switching no physical copper path is established in advance between sender and receiver. Instead when the sender
has a block of data to be sent, it is stored in first switching office, then forwarded later, one jump at a time.
7. How does transmission take place across networks?
The connecting cables that link various workstations.
8. What are communication channels? Discuss various communication channels available for networks.
Communication channels mean the connecting cables that link various workstations.
Various communication channels available for networks:-
(i) Twisted-Pair Cables:- These cables consist of two insulated copper wires twisted around each other. These are also used for
short and medium range telephone communication.
(ii) Coaxial Cables:- A coaxial cable consists of one or more small cables in protective covering. These are more expensive than
twisted pair cables but perform better.
(iii) Fiber-optic Cables:- These cables are made of plastic or glass and are about as thick as human hair. These cables are highly
durable and offer excellent performance but are expensive.
• Above given media are guided media. Unsigned communication media are microwaves, radio waves and satellites.
9. What is bandwidth? How it measured?
Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the bandwidth.
• While bandwidth is traditionally expressed in bits per second (bps), modern network links have greater capacity, which is
typically measured in millions of bits per second (megabits per second, or Mbps) or billions of bits per second (gigabits per
second, or Gbps).
10. What do you understand by data transfer rates?
The data transfer rate represents the amount of data transferred per second by a communications channel or a computing or
storage device.
• Data rate is measured in units of bits per second (bps), bytes per second (Bps), or baud.
• When applied to data rate, the multiplier prefixes "kilo-", "mega-", "giga-", "tera-" etc. (and their abbreviations, "k", "M'", "G",
"T" etc.) always denote powers of 1000.
