This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Advantages of Filter Method”.
1. Which of the following does not cause losses in optical fibre cables?
a) Stepped index operation
d) Light absorption
Explanation: In Stepped index operation, refractive index within the core is uniform. There is also a sharp decrease in refractive index at the core-cladding interface. It generally does not cause any type os losses in optical fibre cables.
2. In case of FM, if the modulating frequency is lowered and the modulating voltage remains constant then the amplitude of distant sidebands first increases and then decreases.
Explanation: If the modulating frequency in FM lowered and the modulating voltage remains constant then the amplitude of distant sidebands increases, as the modulating frequency has no role to play in determining the amplitude of the sidebands.
3. It is generally observed that a ship to ship communication suffers from fading. This problem can be avoided by using ________
a) space diversity
b) frequency diversity
c) directional antenna
Explanation: It is generally observed that a ship to ship communication suffers from fading. This problem can be avoided by using frequency diversity in which the components of a radio wave are received from different channels thus reducing the error that occurs in the transmission of a single frequency component.
4. What is the characteristic impedance of a twin wire feeder used in television?
a) 1000 ohm
b) 100 ohm
c) 10 ohm
d) 300 ohm
Explanation: Twin wire feeder consists of two wires with spacers. For a twin wire feeder the characteristic impedance should be close to 300 ohm.
5. A buffer amplifier is a cathode follower double tuned amplifier.
Explanation: Gain of an amplifier is it’s ability to increase the voltage at the input and produce the result at the output. A buffer amplifier is basically a high gain DC amplifier. It is basically used for transferring voltage from a high output impedance level to a low input impedance level circuit.
6. What is the direction of rotation of a CD?
c) either clockwise or anticlockwise depend on data stored
d) first anticlockwise and then clockwise
Explanation: CD stands for compact disk. The direction of rotation of Compact Disk is anticlockwise.
7. According to Fourier Analysis a square wave can be represented as a fundamental sine wave and even harmonics.
Explanation: A square wave is a periodic non-sinusoidal waveform with an uniform frequency, in which the amplitude alternates between a fixed maximum and minimum value. According to Fourier analysis, a square wave can be represented as an infinite sum of sinusoidal waves. A square wave consists of only components of odd integer harmonics.
8. Filter method is the one and only method to produce SSB?
Explanation: SSB can be produced by filter method also known as frequency discrimination method. It can also be produced by phase discrimination method.
9. Impulse noise can be reduced in _________
Explanation: Impulse noise includes unwanted, almost instantaneous sharp sounds. It is only in frequency modulated circuits that allows reduction in impulse noise.
10. In televisions, equalizing pulses are sent during __________
a) horizontal blanking
b) vertical blanking
d) horizontal retrace
Explanation: The duration of an equalizing pulse is approximately 2.5 microseconds. The repetition frequency of equalizing pulses is twice the line frequency. It is necessary to sent equalizing pulses during horizontal blanking in televisions.
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.