This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Hilbert Transform”.
1. If a receiver has poor selectivity then it also have poor ________
b) blocking of unwanted signals
c) double spotting
Explanation: Selectivity is the property of a radio to respond only to the signals it is tuned to and reject other signals. If a radio receiver has poor selectivity then it also has poor blocking.
2. For a large amount of power, a push pull amplifier is designed for operation as ________
a) class C
b) class B
c) class AB
d) class A
Explanation: A push pull amplifier is generally used whenever a large amount of power is required. For getting a large power it is essential to operate push pull amplifier as a class B amplifier.
3. In a Vidicon camera tube, the side of target plate facing the light has a coating of antimony trisulphide and the side facing electron gun has a coating of tin oxide.
Explanation: In a Vidicon camera tube, the side of target plate facing the light has a coating of 〖Sno〗_2 and the side facing electron gun has a coating of antimony trisulphide.
4. Autocorrelation function of which noise is a constant?
a) white noise
b) shot noise
c) transit noise
d) extraterrestrial noise
Explanation: White noise or thermal noise or Johnson noise is an interior type of noise in communication system. It is a random signal having equal intensities at different frequencies which gives it a constant power and autocorrelation function.
5. Thermal noise, shot noise and transit time noise is part of internal noise in communication.
Explanation: Internal noise in communication is the noise that gets generated within the receiver or communication system. It may be put into the following categories: thermal noise, shot noise, transit time noise.
6. In amplitude modulation, magnitude of side bands is 2ma times the carrier amplitude.
Explanation: In amplitude modulation, magnitude of side bands is 4ma times the carrier amplitude.
7. In frequency modulation, there is a large increase in noise and hence decrease in the signal to noise ratio.
Explanation: In frequency modulation, there is a large decrease in noise and hence increase in the signal to noise ratio.
8. The output of a battery eliminator is closed to ________
a) 70V DC
b) 70V AC
c) 6V AC
d) 6V DC
Explanation: Battery eliminator is used to deliver electrical power without the need for multiple batteries. Its output power is approximately 6V.
9. In India, the subcarrier frequency for transmission of color difference signals in television is approximately ________
a) 10.47 MHZ
b) 5.4 MHZ
c) 7.67 MHZ
d) 1.3 MHZ
Explanation: Subcarrier is actually a sideband of a frequency carrier wave. It is modulated to send additional information. In India the subcarrier frequency for transmission of color difference signals in television is approximately 1.3 MHz.
10. The advantage of using mechanical filter in filter system of sideband suppression is good attenuation characteristics.
Explanation: The advantage of using mechanical filter in filter system of sideband suppression is smaller size, good band pass, good attenuation characteristics.
Sanfoundry Global Education & Learning Series – Analog Communications.
To practice all areas of Analog Communications, here is complete set of 1000+ Multiple Choice Questions and Answers.