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Free download in PDF Analog Communication Multiple Choice Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(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
(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
(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
(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
(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
(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
(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
(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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