This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “RF Mixing”.
1. For a periodic function, the spectral density and auto-correlation functions are ________
a) Laplace transform pair
b) Fourier transform pair
c) Gauss transform pair
d) Hartley transform pair
Explanation: Fourier transform breaks a function into an alternate representation, characterized by sine and cosines. If a function is periodic, the spectral density and auto-correlation functions are Fourier transform pair.
2. Spectral density express________
a) Average voltage
b) Average power in a waveform as a function of frequency
c) Average current
d) Average impedance
Explanation: Power Spectral Density (PSD) of any signal describes the power present in signal as a function of frequency.
3. What is the role of channel in communication system?
a) acts as a medium to send message signals to its medium
b) converts one form of signal to other
c) allows mixing of signals
d) helps to extract original signal from incoming signal
Explanation: Channel acts as a medium to transmit message signal to its medium. Noise gets involved in signal in channel only. Transducer converts one form of energy to other form.
4. For a Gaussian process, auto correction also implies _________
a) Statistical dependance
b) Statistical independence
c) Statistical distribution
d) Ergodic process
Explanation: For a Gaussian process, auto correction implies statistical independence. It is basically a stochastic process.
5. What will be the value of modulation if we want maximum undistorted transmitted power?
Explanation: For getting maximum undistorted power in any modulated system, then modulation index of that system should be 1.
6. Agreement between communication devices are called ________
a) Transmission medium
Explanation: Protocol allows two or more entities of communication system to transmit information. Transmission medium is the path through which information travels.
7. For providing two or more voice circuits on the same carrier, we can use _________
b) ISB systems
d) SSB with pilot carrier
Explanation: ISB systems used provide same carrier to two or more voice circuits.
8. The output stage of television transmitters is most likely to be a __________
a) Grid modulated class C amplifier
b) Grid modulated class A amplifier
c) Plate modulated class C amplifier
d) Plate modulated class A amplifier
Explanation: The output stage of television transmitters are basically class C amplifiers. It is grid modulated.
9. Modulation is used to separate differing transmission.
Explanation: Modulation is the property of varying one or more properties of a periodic waveform. It is used for separating different transmission.
10. A function f(x) is odd, when?
a) f(x) = -f(x)
b) f(x) = f(-x)
c) f(x) = -f(x)f(-x)
d) f(x) = f(x)f(-x)
Explanation: A function f(x) is said to be odd, when f(x) is equal to -f(-x). For an even function f(x) must be equal to f(-x).
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.