This set of Analog Communications Multiple Choice Questions & Answers (MCQs) focuses on “Receiver”.
1. Demodulation is done in ________
b) Radio Receiver
c) Receiving antenna
Explanation: Demodulation means extracting the original signal from a carrier wave. The extraction of original signal is generally used with radio receiver.
2. What is Fidelity?
a) Equally amplifies all the signal frequencies at receiver
b) Ability of receiver to select wanted signal from various incoming signal
c) Minimum magnitude of input signal required to produced a specified output
d) Process of varying one or more properties of carrier signal
Explanation: Fidelity is the ability of amplifier to reproduce input signal without any distortion. The ability of receiver to select wanted signal from various incoming signal is called Selectivity while sensitivity is the minimum magnitude of input signal required to produced a specified output. And the process of varying one or more properties of carrier signal is called modulation.
3. In a receiver, noise is usually developed at ________
a) Audio stage
b) Receiving antenna
c) RF stage
d) IF stage
Explanation: Ability of radio receiver to pick up required level of radio signals will enable it to operate more effectively. All the methods that are used to make receiver more sensitive use the fact that the limiting factor of the sensitivity is not the level of amplification available, but the levels of noise that are present within the radio receiver or outside.
4. Which oscillator is used as a local oscillator in radio receiver?
d) Phase Shift
Explanation: In Hartley oscillator, the oscillation frequency is determined by a tuned circuit. It generally consists of capacitors and inductors i.e. an LC oscillator. Generally used as a local oscillator in radio receiver.
5. Process of recovering information signal from received carrier is known as ________
Explanation: Detection means extracting information Contained in a modulated carrier wave while minimum magnitude of input signal required to produced a specified output is Sensitivity. Ability of receiver to select wanted signal from various incoming signal is called Selectivity and Multiplexing means sending multiple signals over a communication link at the same time in the form of a single complex signal.
6. What is the use of varacter diode in radio receiver?
Explanation: Varacter diode is a tuning diode having variable capacitance, they are operated in reverse bias. Therefore there is no flow of current in it.
7. What is the function of radio receiver?
a) to detect and amplify information signal from the carrier
b) to transmit message
c) to process the electrical signal from different aspects
d) to convert one form of energy into other
Explanation: Channel is a medium through which a message is transmitted. Transmitter is used process the electrical signal from different aspects. Transducer is used to convert one form of energy into another form and the role of receiver is to detect and amplify information signal from the carrier.
8. Figure of merit is ________
a) Ratio of output signal to noise ratio to input signal to noise ratio
b) Ratio of input signal to noise ratio to output signal to noise ratio
c) Ratio of output signal to input signal to a system
d) Ratio of input signal to output signal to a system
Explanation: Figure of merit is a numerical quantity based on characteristic of system that represents a measure of efficiency or effectiveness. It is defined as the ratio of output signal to noise ratio to input signal to noise ratio.
9. Superheterodyne principle provides selectivity at ________
a) RF stage
b) IF stage
c) Before RF stage
Explanation: A superheterodyne receiver works as normal radio receiver. It uses frequency mixing to convert received signal to a fixed intermediate frequency (IF) which can be processed more conveniently than original carrier frequency.
10. A heterodyne frequency changer is ________
Explanation: A mixer is a nonlinear electrical circuit that creates new frequencies from two signals applied to it. Mixers are widely used to shift signals from one to other frequency range, which is known as heterodyning process.
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.