Analog Communications Multiple Choice Questions focuses on “ZCD”.
1. MAU stands for __________
a) Multiple Access Unit
b) Multi-station Access Unit
c) Multiple Auxiliary Unit
d) Multi-station Auxiliary Unit
Answer: b
Clarification: MAU stands for the Multi-station Access Unit. It acts as a hub that connects a group of computers to a token ring local area network.
2. Packet switching is based on ________
a) switched circuits
b) un-switched circuits
c) store-and-forward
d) real time delivery
Answer: c
Clarification: Packet switching is a method of grouping data transmitted over a network into packets. It has two modes of operation: Connectionless Packet Switching and Connection-Oriented Packet Switching. It is based on a store and forward algorithm.
3. What is used for setting up a virtual circuit?
a) frame
b) network
c) link
d) hub
Answer: b
Clarification: For the creation of any virtual circuit, a network is must required.
4. Which modulation is used in high frequency radio-teletype systems?
a) QAM
b) ASK
c) PSK
d) FSK
Answer: d
Clarification: Frequency Shift Keying is a type of frequency modulation. In it, data is transmitted through discrete frequency changes of a carrier signal. It is highly used in frequency radio-teletype systems.
5. When we use TDMA instead of TDM?
a) when signals come from different sources
b) when all the signals come from same source
c) when all the signals contain the same information
d) when all the signals contain different information
Answer: a
Clarification: If all the signals comes from different types of sources, then it is better to use TDMA instead of TDM.
6. The effect of frequency on the resistance of a wire is called ________
a) skin effect
b) I2R loss
c) ohmic effect
d) threshold effect
Answer: a
Clarification: Skin effect becomes more and more apparent as frequency increases as skin depth becomes smaller. It is due to alternating current flowing through the outer surface of conducting material. It refers to the increase of wire resistance with frequency.
7. The electric and magnetic field of a radio wave are perpendicular to each other.
a) True
b) False
Answer: a
Clarification: The statement is correct that both fields are perpendicular to each other. They are also perpendicular to the direction of propagation.
8. Which polarization is possible for an electromagnetic wave?
a) vertical
b) circular
c) horizontal
d) can be vertical or horizontal or circular
Answer: d
Clarification: In electromagnetic waves, both electric and magnetic fields are present. Polarization states the orientation of electric flux lines in EM field. Thus it can be vertically polarized or horizontally or circularly polarized.
9. On which factor dominant mode of a waveguide depends?
a) shape
b) power
c) direction
d) bandwidth
Answer: a
Clarification: A waveguide is something that guides waves, such as electromagnetic wave or sound with minimum loss of energy. The dominant mode of a waveguide depends on the shape of the waveguide.
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