This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Quadrature Carrier Multiplexing”.
1. The output stage in a television transmitter is likely to be ________
a) screen modulated
b) plate modulated
c) rectangular modulated
d) grid modulated
Explanation: We generally use vestigial sideband for television production. VSB is used because it reduces the required bandwidth. The output stage in a television transmitter is generally grid modulated.
2. The advantage of using mechanical filter in filter system of sideband suppression is good band pass.
Explanation: The advantage of using mechanical filter in filter system of sideband suppression is smaller size, good band pass, good attenuation characteristics.
3. Television transmission is possible through ________
Explanation: We generally use vestigial sideband (VSB) for television production. VSB is used because it reduces the required bandwidth to half.
4. The rms value of a thermal noise voltage is proportional to (where k is Boltzmann’s constant) _______
Explanation: The root means square value of thermal or white noise is proportional to root k times, where k represents Boltzmann’s constant.
5. For a human eye the minimum viewing angle of resolution should be ʎ⁄D where D is iris opening and ʎ is wavelength of light.
Explanation: For a human eye the minimum viewing angle of resolution should be 1.22ʎ/D. The diameter of human eye is about 25mm.
6. In amplitude modulation, magnitude of side bands is ________ times the carrier amplitude.
Explanation: In amplitude modulation, for a good transmission and reception the magnitude of side bands must be 4ma times the amplitude of carrier wave.
7. Noises which get generated within the receiver is called ________
a) Internal noise
b) External noise
c) Man-made noise
d) Default noise
Explanation: Internal noise in communication is the noise that gets generated within the receiver or communication system.
8. Autocorrelation function of white noise is ________
a) an impulse function
b) a step function
c) a constant
d) a variable
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.
9. In a Vidicon camera tube, the side of target plate facing the light has a coating of Sno2 (tin oxide) and the side facing electron gun has a coating of antimony trisulphide.
Explanation: In a Vidicon camera tube, the side of target plate facing the light has a coating of Sno2 and the side facing electron gun has a coating of antimony trisulphide.
10. Marconi antenna ________
a) is a grounded antenna
b) is an ungrounded antenna
c) can either be grounded or ungrounded antenna
d) can neither be grounded nor ungrounded antenna
Explanation: Marconi antenna is like a vertical wire having length one fourth of the working wavelength. It requires a ground plane with very good conductivity. Hence it is also called as a grounded antenna.
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.