laboursonline – MCQs, Mock Tests | Electrical measurements Digital Communications MCQs set-13

Which method is efficient?

1. Fixed assignment
2. Dynamic allocation
3. Fixed assignment & Dynamic allocation
4. None of the mentioned

✅ Correct Answer: 3

The preamble consists of

1. Synchronization
2. Addressing
3. Error control sequence
4. All of the mentioned

✅ Correct Answer: 4

Each satellite has ______ transponders.

1. 10
2. 12
3. 15
4. 18

✅ Correct Answer: 2

In spread spectrum technique, the desired signal is multiplied _____ and interference signal is multiplied _____

1. Once, twice
2. Twice, once
3. Twice, thrice
4. Thrice, twice

✅ Correct Answer: 2

Uncertainty in the delay measurement is _______ to rise time of the pulse.

1. Directly proportional
2. Inversely proportional
3. Not related
4. None of the mentioned

✅ Correct Answer: 1

Which has a lesser average packet delay?

1. FDMA
2. TDMA
3. Dynamic FDMA
4. None of the mentioned

✅ Correct Answer: 2

The maximum waiting time before transmission of a packet is

1. (M-1)T/M
2. (M-1)M/T
3. (M+1)T/M
4. (M+1)M/T

✅ Correct Answer: 1

CDMA is

1. Similar to FDMA
2. Similar to TDMA
3. Combination of both
4. None of the mentioned

✅ Correct Answer: 3

Frequency modulation technique involves

1. Data modulation
2. Frequency hopping modulation
3. Data & Frequency hopping modulation
4. None of the mentioned

✅ Correct Answer: 3

Which needs precise time coordination?

1. CDMA
2. TDMA
3. CDMA & TDMA
4. None of the mentioned

✅ Correct Answer: 2

A local area network can be used to interconnect

1. Computers
2. Terminals
3. Printers
4. All of the mentioned

✅ Correct Answer: 4

LAN uses _________ cables.

1. Low bandwidth
2. High bandwidth
3. Low & High bandwidth
4. None of the mentioned

✅ Correct Answer: 2

The maximum packet size of Ethernet is

1. 1426 bytes
2. 1526 bytes
3. 1256 bytes
4. 1626 bytes

✅ Correct Answer: 2

The minimum packet size of Ethernet is

1. 81 bytes
2. 75 bytes
3. 72 bytes
4. 64 bytes

✅ Correct Answer: 3

The interface between the ring and the stations are passive.

1. True
2. False
3.
4.

✅ Correct Answer: 2

Bit stuffing is done by inserting _____, after ____ consecutive ones.

1. Zero, seven
2. Zero, five
3. One, seven
4. One, five

✅ Correct Answer: 1

As channel capacity increases, channel throughput

1. Increases
2. Decreases
3. Remains the same
4. None of the mentioned

✅ Correct Answer: 1

In Aloha technique, the re-transmission takes place immediately.

1. True
2. False
3.
4.

✅ Correct Answer: 2

In which technique, packet size are constant?

1. Pure Aloha
2. Slotted Aloha
3. Pure & Slotted Aloha
4. None of the mentioned

✅ Correct Answer: 1

For a throughput of value less than 0.20, which has less average delay?

1. S-ALOHA
2. Pure ALOHA
3. R-ALOHA
4. None of the mentioned

✅ Correct Answer: 1

For a throughput value of 0.20 to 0.67, which has less average delay?

1. S-ALOHA
2. Pure ALOHA
3. R-ALOHA
4. None of the mentioned

✅ Correct Answer: 3

Binary tree search is used for

1. Multiple users
2. Single users
3. Single & Multiple users
4. None of the mentioned

✅ Correct Answer: 1

Which method is better suited for large population?

1. Straight polling
2. Binary tree search
3. Straight polling & Binary tree search
4. None of the mentioned

✅ Correct Answer: 2

For a higher throughput value which method works efficiently?

1. S-ALOHA
2. Pure ALOHA
3. R-ALOHA
4. None of the mentioned

✅ Correct Answer: 3

INTELSAT II and III operates their TWTA in

1. Saturation region
2. Linear region
3. Hard limiting region
4. None of the mentioned

✅ Correct Answer: 2

As the number of carriers, the capacity of the transponder

1. Increases
2. Decreases
3. Remains the same
4. None of the mentioned

✅ Correct Answer: 2

As the number of carriers increases, the number of guard bands

1. Increases
2. Decreases
3. Remains the same
4. None of the mentioned

✅ Correct Answer: 1

TWTA which operates in the linear region

1. Reduces interference
2. Provide less overall power
3. Is power limited
4. All of the mentioned

✅ Correct Answer: 4

Which method is better when traffic is heavy?

1. SPADE
2. Binary tree search
3. SPADE & Binary tree search
4. None of the mentioned

✅ Correct Answer: 3

SPADE uses

1. QPSK
2. BPSK
3. FSK
4. MSK

✅ Correct Answer: 1

SPADE is a

1. MAA system
2. DAMA system
3. MAA & DAMA system
4. None of the mentioned

✅ Correct Answer: 2

In SPADE system, the carrier is done based on

1. Fixed assignment
2. Demand assignment
3. Fixed & Demand assignment
4. None of the mentioned

✅ Correct Answer: 2

Which is more costlier?

1. TDMA
2. FDMA
3. ALOHA
4. None of the mentioned

✅ Correct Answer: 1

Which technique needs precise synchronization?

1. TDMA
2. FDMA
3. TDMA & FDMA
4. None of the mentioned

✅ Correct Answer: 1

Which is based on orthogonality?

1. TDM
2. FDM
3. TDM & FDM
4. None of the mentioned

✅ Correct Answer: 2

Which provides constant delay?

1. Synchronous TDM
2. Non synchronous TDM
3. Synchronous & Non synchronous TDM
4. None of the mentioned

✅ Correct Answer: 1

Example of reservation system is

1. Synchronous TDM
2. Non synchronous TDM
3. Synchronous & Non synchronous TDM
4. None of the mentioned

✅ Correct Answer: 3

Reservation systems are useful when

1. Delay is small
2. Delay is large
3. Delay is small or large
4. None of the mentioned

✅ Correct Answer: 2

In slotted system, access is

1. Synchronous
2. Asynchronous
3. Synchronous & Asynchronous
4. None of the mentioned

✅ Correct Answer: 2

In CSMA, collision window is _____ to cable length.

1. Equal
2. Greater
3. Lesser
4. None of the mentioned

✅ Correct Answer: 2

Which isolates collision?

1. Bridges
2. Routers
3. Bridges & Routers
4. None of the mentioned

✅ Correct Answer: 3

Minimum packet size increases as

1. Speed increases
2. Distance increases
3. Speed & Distance increases
4. None of the mentioned

✅ Correct Answer: 3

Which are non orthogonal multiplexing?

1. TDM
2. FDM
3. TDM & FDM
4. None of the mentioned

✅ Correct Answer: 4

Companding is used to

1. Increase the information transmission rate
2. Use only one carrier frequency to handle different signals
3. To use different frequency bands for different signals
4. To protect all small signals in PCM from quantizing noise

✅ Correct Answer: 4

TDM is used to

1. Increase the information transmission rate
2. Use only one carrier frequency to handle different signals
3. To use different frequency bands for different signals
4. To protect all small signals in PCM from quantizing noise

✅ Correct Answer: 2

Which has greater bandwidth?

1. TDM
2. FDM
3. TDM & FDM
4. None of the mentioned

✅ Correct Answer: 2

Which has lower noise immunity?

1. TDM
2. FDM
3. TDM & FDM
4. None of the mentioned

✅ Correct Answer: 1

TDM can be employed to transmit channels having unequal bandwidth,

1. True
2. False
3.
4.

✅ Correct Answer: 1

Using sampling theorem, analog signal cannot be reconstructed.

1. True
2. False
3.
4.

✅ Correct Answer: 2

Which maintains better fidelity?

1. Analog communication
2. Digital communication
3. Analog & Digital communication
4. None of the mentioned

✅ Correct Answer: 2