Question

Assertion(A): To transmit low frequency audio signals over long distances, the audio signals are superimposed on a high frequency carrier signal.
Reason(R): Low frequency audio signals cannot be transmitted directly over long distances.

• A. A and R are true and R is the correct explanation of A
• B. A and R are true but R is not correct explanation of A
• C. A is true but R is false
• D. A is false but R is true.

Answer 1

Answer: (A)

A and R are true and R is the correct explanation of A

Low frequency signals has very low strength and thus, they die down during the propagation (because of noise creeping in), thus they are superimposed on high frequency signals. Moreover, audio waves are mechanical waves which need a medium to traverse but the superimposed signal is electromagnetic and thus, can travel to a large distance.