Question

If a radio receiver amplifier amplifies all the signal frequencies equally well, it is said to have:
(A) Sensitivity
(B) Selectivity
(C) Distortion
(D) Fidelity

Answer 1

Hint
Sensitivity and Selectivity are the terms which are confined to only receivers. They are not related to the amplifier part of the circuit. Distortion and fidelity are terms generally used with the amplifier part of the circuit. In this question, we need to consider the amplifier. This eventually narrows down the solution to distortion and fidelity.

Complete step by step answer
The sensitivity of a receiver is defined as the quality of response that can be attained without interference from any other substance or it can be said as the ability to identify and then amplify the desired weak signal. Selectivity is defined as the ability of a radio receiver to filter out only the selected or wanted signal. Both of these terms are exclusive for the radio receiver only. Distortion is the condition when the wave is distorted by superimposing with a different undesirable wave. This should be minimized as much as possible. Fidelity is the condition when a radio amplifier can amplify the frequency equally well.
Therefore, the option with the correct answer is option (D).

Note
Fidelity and distortion are not only limited to the frequency of the waves, but they also occur with the amplitude of the wave. A wave’s amplitude distortion occurs when the output amplitude is not a linear function of the input amplitude. However, the fidelity of the amplitude is of little significance and is often ignored.