Question

A signal m(t) with bandwidth 500 Hz is first multiplied by a signal g(t). The resulting signal is passed through an ideal low pass filter with bandwidth 1 kHz. The output of the low pass filter would be :

(a) Impulse

(b) m(t)

(c) 0

(d) m(t)del(t)

The question was posed to me in homework.

I'm obligated to ask this question of Spectrum Analysis of Sampling Process topic in chapter Digital Control Systems of Control Systems

Answer 1

Correct answer is (c) 0

The explanation is: m (t) g (t)->M (f)*G (f)

After low pass filtering with fc =1 kHz, hence the output is zero.