250+ TOP MCQs on Modulation Techniques and Answers

Computer Fundamentals Questions and Answers for Aptitude test on “Modulation Techniques”.

1. A coaxial cable has a bandwidth of _________ of megahertz.
a) 100
b) 150
c) 1000
d) 10000

Answer: a
Clarification: A coaxial cable has a bandwidth of 100’s of Mhz. Baseband speed is in a few KHz. Multiplexing improves channel bandwidth utilization.

2. In TDM, the samples occupy adjacent time slots.
a) True
b) False

Answer: a
Clarification: The statement is true. The TDM technique is based on sampling and they occupy adjacent slots and are transmitted in a sequence.

3. The carrier wave is a _________
a) tan wave
b) cosec wave
c) sine wave
d) cot wave

Answer: c
Clarification: The carrier wave is generally a sine wave. Carrier wave is used to transfer the signal from source to destination.

4. Controlling the phase is referred as __________
a) modulation
b) half modulation
c) amplitude modulation
d) phase modulation

Answer: d
Clarification: It is referred to as phase modulation. When there is a change in amplitude, it is referred to as amplitude modulation.

5. A transmission mode that can transmit data in both the directions but transmits in only one direction at a time.
a) simplex
b) half duplex
c) full duplex
d) semi-duplex

Answer: b
Clarification: The half duplex mode supports two way traffic but only in one direction at a time.

6. A multiplexing technique based on sampling.
a) FDM
b) TDM
c) SDM
d) FM

Answer: b
Clarification: TDM which stands for Time division multiplexing is based on sampling which is a modulation technique.

7. An example of FDM:
a) broadcast radio
b) telephone
c) machines
d) semi-duplex

Answer: a
Clarification: Broadcast radio is an example of FDM. This allows several messages to be translated from baseband.

8. FDM stands for?
a) Frequency Division Multiplexing
b) Frequency Dependent Multiplexing
c) Frequency Diverged Multiplexing
d) Frequency Derived Multiplexing

Answer: a
Clarification: FDM stands for Frequency Division Multiplexing. This allows several messages to be translated from baseband, where they are all in the same frequency.

9. A modulation technique that improves channel bandwidth utilization.
a) direct
b) modulation
c) demodulation
d) multiplexing

Answer: d
Clarification: Multiplexing is a modulation technique that improves channel bandwidth utilization.

10. The purpose of communication system is to transfer information from _______ to the destination.
a) user
b) source
c) system
d) station

Answer: b
Clarification: The answer is source. A communication system transfers information from source to the destination.