Question

In AM waves, the amplitude of sideband frequency is
A. ${{E}_{c}}$
B. $m{{E}_{c}}$
C. $\dfrac{m{{E}_{c}}}{2}$
D. $2m{{E}_{c}}$

Answer 1

In this question we have been asked to calculate the amplitude of sideband frequency of the amplitude modulation waves. To solve this question, we shall define what is amplitude modulation and also describe why are the sidebands created. We shall then try to calculate the amplitude of the given side band frequency.

Complete answer:
Amplitude modulation is a technique used in communication for transmitting the messages with radio carrier waves. In Amplitude modulation the message is transmitted by varying the signal strength or amplitude of the carrier wave.
Now, while modulating the amplitude, a band of frequencies higher or lower than the carrier frequencies is generated. These frequencies are known as the sidebands frequencies. These sidebands carry the spectral component of the modulated wave except the carrier. These sidebands occur in pairs on either side of carrier frequency at equal distance from the modulated frequency. Amplitude modulation involves mixing of carrier and information signal. We know that the information is carried by side bands as well.
We know that the amplitude of sideband frequency is given by, $\dfrac{m{{E}_{c}}}{2}$ where, ${{E}_{c}}$ is the frequency of the carrier signal.

Note:
The Amplitude modulation is very often used in broadcasting. The demodulation of these signals is very easy. This makes the receivers of amplitude modulation signals cheaper and easy to manufacture. However, the AM signals are strongly affected by electrical storms and other frequencies. Although radio transmitters can transmit sound waves of higher frequency, the receivers are not capable of reproducing these high frequency signals.