Analog Communication MCQs | Analog Communication Multiple Choice Questions and Answers

Questions
1 How we limit the response of a receiver to a weak signal?
A by the AGC
B by the noise that is generated in the receiver
C by the dynamic range of the receiver
D by the type of detector circuit being used

Answer: by the noise that is generated in the receiver
2 Which statement is true for high level amplitude modulation?
A all RF amplifiers can be nonlinear
B all RF amplifiers are of class A
C minimum RF power is required
D maximum RF power is required

Answer: all RF amplifiers can be nonlinear
3 Which two networks can be used for impedance matching?
A pi network and T network
B bridge network and T network
C pi network and omega network
D pi network and bridge network

Answer: pi network and T network
4 Which statement is true about frequency multipliers?
A they are essentially class C amplifiers
B they are essentially balanced modulators
C they are essentially class AB amplifiers
D they are essentially mixers

Answer: they are essentially class C amplifiers
5 Drawback of using PAM method is
A Bandwidth is very large as compared to modulating signal
B Due to varying amplitude of carrier, it is difficult to remove noise at receiver
C Varying amplitude of carrier varies the peak power required for transmission
D All of the above

Answer: All of the above
6 In Pulse time modulation (PTM),
A Position or width of the carrier varies with modulating signal
B Pulse width modulation and pulse position modulation are the types of PTM
C Amplitude of the carrier is constant
D All of the above

Answer: All of the above
7 In Pulse Position Modulation, the drawbacks are
A Synchronization is required between transmitter and receiver
B Large bandwidth is required as compared to PAM
C None of the above
D Marketing

Answer: Both a and b
8 In pulse width modulation,
A Instantaneous power at the transmitter is constant
B Amplitude of the carrier pulse is varied
C Synchronization is not required between transmitter and receiver
D None of the above

Answer: Synchronization is not required between transmitter and receiver
9 In PWM signal reception, the Schmitt trigger circuit is used
A To produce ramp signal
B For synchronization
C To remove noise
D None of the above

Answer: To remove noise
10 What we use for impedance matching in RF amplifiers?
A RC coupling
B Transformer coupling
C Direct coupling
D RF coupling

Answer: Transformer coupling
11 In a receiver, distortion can occur in ________
A Mixer
B Detector
C IF amplifiers
D Either mixer or detector or IF amplifiers

Answer: Either mixer or detector or IF amplifiers
12 When aliasing will take place?
A Sampling signals more than Nyquist Rate
B Sampling signals equal to Nyquist Rate
C Sampling signals at a rate which is twice of Nyquist Rate
D Sampling signals less than Nyquist Rate

Answer: Sampling signals less than Nyquist Rate
13 Which statement is true for low level amplitude modulation?
A all RF amplifiers can be linear
B all RF amplifiers are of class A
C minimum RF power is required
D maximum RF power is required

Answer: all RF amplifiers can be linear
14 Notch filter is a
A Band pass filter
B Low pass filter
C High pass filter
D Band stop filter

Answer: Band stop filter
15 Noise power at the resistor is affected by the value of the resistor as
A Unaffected by the value of the resistor
B Directly proportional to the value of the resistor
C Inversely proportional to the value of the resistor
D Becomes half as the resistance value is doubled

Answer: Unaffected by the value of the resistor
16 At a room temperature of 300K, calculate the thermal noise generated by two resistors of 10KΩ and 30 KΩ when the bandwidth is 10 KHz and the resistors are connected in parallel.
A 30.15 * 10-3
B 11.15 * 10-7
C 8.23 * 10-23
D 26.85 * 10-7

Answer: 11.15 * 10-7
17 A periodic signal is
A May be represented by g(t) = g(t + T0)
B Value may be determined at any point
C Repeats itself at regular intervals
D All of the above

Answer: All of the above
18 Properties of Hilbert transform are:
A The signal and its Hilbert transform have same energy density spectrum
B The signal and its Hilbert transform are mutually diagonal
C Both a and b are correct
D None of the above

Answer: Both a and b are correct
19 Random signals is
A May be specified in time
B Repeat over a period
C Occurrence is random
D None of the above

Answer: Occurrence is random
20 The rms value of thermal noise voltage is related to Boltzmann’s constant k as
A Vn is Directly proportional to √k
B Vn is Directly proportional to k2
C Vn is Directly proportional to k
D Vn is Directly proportional to k3

Answer: Vn is Directly proportional to √k
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