Question

Given below are two statements : 
Statement I : For transmitting a signal, size of antenna ( $f$ ) should be comparable to wavelength of signal (at least $l=\frac{\lambda}{4}$ in dimension)
Statement II : In amplitude modulation, amplitude of carrier wave remains constant (unchanged) 
In the light of the above statements, choose the most appropriate answer from the options given below,

• A. Statement I is correct but Statement II is incorrect
• B. Both Statement I and Statement II are incorrect
• C. Both Statement I and Statement II are correct
• D. Statement I is incorrect but Statement II is correct

Hint:

In AM, the carrier wave's amplitude varies in accordance with the modulating signal. It is the phase and frequency of the carrier wave that remain constant.

Answer 1

The Correct Option is A

Statement I: The size of the antenna for efficient signal transmission should be comparable to the wavelength of the signal. Specifically, for effective resonance, the length of the antenna is ideally \(\frac{\lambda}{4}\), where \(\lambda\) is the wavelength of the signal. 
Hence, Statement I is correct.

Statement II: In amplitude modulation (AM), the amplitude of the carrier wave changes depending on the information signal, while the frequency and phase remain constant. Therefore, Statement II is incorrect.

Thus, the correct answer is that Statement I is correct, while Statement II is incorrect.