This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Channel”.
1. Notch is a ________
a) High pass filter
b) Low pass filter
c) Band stop filter
d) Band pass filter
Explanation: Notch filter is a band stop filter since it allows most frequencies to pass through it, except a specific range. It is just opposite of a band-pass filter.
2. Sin wave is ________
a) Aperiodic Signal
b) Periodic Signal
c) Random Signal
d) Deterministic Signal
Explanation: Periodic signal is that which repeat it’s value after some interval. Sin wave is a periodic function since it’s value may be determined at any point of time since it repeats itself at regular intervals of time.
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. Sum of a periodic and aperiodic signal always be a aperiodic signal.
Explanation: No, the sum of a periodic and aperiodic signal can be periodic. For example
Let f(x) = sin(x), which is a periodic function with period 2π and g(x) = −sin(x) + sin(√2x), which is an aperiodic function. Now the sum of both i.e. f(x) + g(x) = sin(√2x) which is a periodic function.
5. Noise is added to a signal ________
a) In the channel
b) At receiving antenna
c) At transmitting antenna
d) During regeneration of information
Explanation: Noise is an unwanted signal that gets mixed with the transmitted signal while passing through the channel. The noise interferes with the signal and provides distortion in received signal.
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. What is the advantage of superheterodyning?
a) High selectivity and sensitivity
b) Low Bandwidth
c) Low adjacent channel rejection
d) Low fidelity
Explanation: The main advantage of superheterodyning is that it has high selectivity and sensitivity. Its bandwidth remains same. Moreover, it has high adjacent channel rejection.
8. Low frequency noise is ________
a) Flicker noise
b) Shot noise
c) Thermal noise
d) Burst noise
Explanation: Power spectral density of flicker noise increases with decrease in frequency. It is generated due to the fluctuations in the density of carrier.
9. Relationship between amplitude and frequency is represented by ________
a) Time-domain plot
b) Phase-domain plot
c) Frequency-domain plot
d) Amplitude-domain plot
Explanation: Relationship between amplitude and frequency is represented by frequency-domain plot. While a time-domain graph shows how a signal changes over time.
10. A function f(x) is even, 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: Geometrically a function f(x) is even if graph of function is symmetric. Algebraically, for any function f(x) to be even, f(x) = 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.