This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Amplitude Limiting”.
1. TRF receivers are used for ________
a) Detection of modulating signal
b) Removal of unwanted signal
c) Removing noise
d) Both detection of modulating signal and removal of unwanted signal
Explanation: TRF receivers are used for detection of modulating signal and removal of unwanted signal. The receiver receive the modulated signal and detect the information signal from received modulating signal.
2. Calculate the power in a DSB-SC signal, if the modulation is 60% and power of carrier wave is 600W?
Explanation: The total power for DSB is PC (m2⁄2) = 600X(0.62⁄2) = 108W.
3. One of the advantage of using analog communication over digital communication is that in analog communication less transmission bandwidth is required?
Explanation: Due to analog to digital conversion, data rate becomes high in digital communication which increases the bandwidth in digital communication.
4. According to Fourier analysis, square wave can be represented as ________
a) fundamental sine wave and even harmonics
b) fundamental sine wave and odd harmonics
c) fundamental sine wave and harmonics
d) fundamental and sub harmonic sine wave
Explanation: A square is a non-sinusoidal periodic waveform in which the amplitude alternates between a fixed maximum and minimum value. According to Fourier analysis, square wave is represented as the limit case of an infinite series of sinusoidal waves. An ideal square wave contains only components of odd integer harmonics.
5. What is the maximum transmission efficiency of an AM signal?
Explanation: The percentage of total power contributed by sidebands of the AM signal is known as transmission efficiency of an amplitude modulated system. The maximum transmission efficiency of an AM signal is 33.33%.
6. Mass of any moving system is represented by ________
a) a resistance
b) a conductance
c) combination of inductor and capacitor
d) an inductance
Explanation: Inductance can also be seen as electromagnetic inertia, a property that opposes changes in electric currents and magnetic fields. Mass has inertia so it is represented by an inductance.
7. Generation of SSB-SC signal is done by ________
a) Phase discrimination method and Frequency discrimination method
b) Phase discrimination method and Product modulator
c) Product modulator and Frequency discrimination method
d) Product modulator and Square law modulator
Explanation: SSB-SC signals are the signals where only one of the side band is transmitted in an AM wave. SSB-SC signal is generated by two methods, frequency discriminator method or filter method and phase discriminator method or phase shift method.
8. Bandwidth of RF amplifier for a color TV receiver is ________
a) equal to channel width
b) more than channel width
c) less than channel width
d) twice of channel width
Explanation: RF amplifiers are tuned amplifiers in which the frequency of operation is controlled by a tuned circuit. Bandwidth of RF amplifier is generally kept a little more than channel so that there is no problem in reception.
9. In automatic gain control of the AM receiver ________
a) gain of the receiver is adjusted
b) gain adjustment depends upon the strength of received signal
c) output provided is an AC voltage
d) required power is very low
Explanation: Automatic Gain Control provides controlled signal amplitude at the output even if there are amplitude variations at the input. This controlled output adjusts the input to output gain to a suitable value.
10. Which of the following is an example of continuous wave analog modulation?
Explanation: Analog communication is a type in which the message to be transmitted is analog in nature. Here the message signal modulates a high frequency carrier signal. In AM, amplitude of carrier is varied with respect to the wave which is propagated. It is also an example of continuous wave analog modulation.
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.