Question

The main purpose of modulation is to
1. combine two waves of different frequencies
2. achieve waveshaping of the carrier wave
3. transmit low frequency information over long distances efficiently
4. reduce sidebands

Answer 1

Correct Answer - Option 3 : transmit low frequency information over long distances efficiently

Modulation is the process in which some characteristics, usually an amplitude, frequency, or phase angle of a high-frequency carrier wave is varied in accordance with the instantaneous value of a low-frequency information signal called modulating signal.

Key Points:

• A low-frequency wave cannot be transmitted to long distances. So, a low-frequency information signal is superimposed on a high-frequency wave, which acts as a carrier of the information.
• A transmitter is a device that processes a message signal into a form suitable for transmission and then transmits it to the receiving end through a transmission medium.
• A receiver is a device that recovers the original message signal from the signal received at the output of the communication channel.