Question

Which of the following wave is known as “amplitude modulated wave” of x(t)?

(a) C.x(t) (where C is a constant)

(b) x(t)+y(t)

(c) x(t).y(t)

(d) dx(t)/dt

This question was posed to me during an online interview.

I would like to ask this question from Signals, Systems and Signal Processing in portion DSP – Basic Signaling of Digital Signal Processing

Answer 1

Right option is (c) x(t).y(t)

For explanation I would say: The multiplicative operation is often encountered in analog communication, where an audio frequency signal is multiplied by a high frequency sinusoid known as carrier. The resulting signal is known as “amplitude modulated wave”.