BHARAT SEVAK SAMAJ
Time: 2hrs. Max. Marks: 100
I. Fill in the blanks: (10 x 1 = 10)
1. The cost of conveying data over a large distance in a communication system should be ..
2. PCs connected with ..can also be used for education, entertainment etc.
3. In digital transmission Baud rate is always smaller or equal to the ..
4. In half-duplex data transmission data can be transmitted in .direction
5. The purpose of twisting the wires is to .the efficiency of the UTP. .
6. STP and . Can be used for both analog and digital data transmission .
7. Higher the band width, the. . is the efficiency response in a stereo system .
8. . Networks use the entire band width of the cable for a signal channel.
9. .is basically a frequency division multiplexed situation.
10. Base band systems use .signal over a single frequency.
II. State whether True or False: (10 x 1 = 10)
1. All modems are direct connecting devices.
2. In half-duplex transmission, data can be simultaneously transmitted in both directions.
3. In time division multiplexing all users shares the channel at the same time.
4. Synchronous transmission does not require start stop information for each character.
5. In frequency division multiplexing every user is allotted a specific time slot.
6. Synchronous transmission is more efficient than asynchronous transmission.
7. CRC is used to verify the integrity of the entire block of data.
8. In full-duplex mode of transmission, the line must turn around each time the direction is reversed.
9. The best example of the TDM is the way we receive various radio stations in a radio.
10. Maintenance of analog communication systems is costly and difficult as compared to digital system.
III. Answer any SIX of the following: (6 x 10 = 60)
1. Differentiate between simplex, half-duplex and full-duplex modes of data transmission.
2. Explain the terms bit rate and baud rate.
3. Differentiate between analog and digital transmission of data. Give their relative advantage and disadvantages.
4. What are modems? What purpose do they serve in data communication systems?
5. Compare the following transmission media: a) twisted pair and optical fibre, b) STP and coaxial cable.
6. Why do you connect the wire mesh conductor of a coaxial cable to the ground?
7. Why the digital communication systems are more resistant to channel noise than analog systems?
IV. Answer any ONE of the following: (1 x 20 = 20)
1. Briefly explain the following i) PABX ii) Transmission media.
2. What is LAN? How does it differ from MAN, CAN and WAN?