Question

How an AM radio station increase its signal-to-noise ratio?

(a) by increasing its modulation index

(b) by decreasing its modulation index

(c) by maintaining a constant modulation index

(d) by increasing the frequency

This question was addressed to me by my college professor while I was bunking the class.

My question comes from Spectrum of AM SC Waves in section Side Band Techniques of Analog Communications

Answer 1

Correct option is (a) by increasing its modulation index

The best explanation: Signal to noise ratio is the ratio of signal power to the noise power. It is the measure of signal present with respect to the surrounding noise. It is directly proportional to the modulation index and thus it increases with modulation index.