Carrier waves are used for communicating signals over long distance, because

Options

A. carrier waves can be generated very easily
B. low frequencies can not be easily modulated by the carrier Waves
C. low frequencies can be transmitted over long distances
D. carrier waves generated at higher frequencies can be transmitted over long distances

Answer

D

Explanation

Low frequency signals have very low energy, hence, they can not transmitted over long distance without modulation. In modulation, characteristics of carrier wave is varies according to the amplitude of low frequency (messages signal). Carrier waves are high frequency signal which are used to transmit a low frequency signal over a long distance by modulation.