Question

The causal continuous system with impulse response should satisfy ____ equation.

(a) h(t)=0,t<0

(b) h(t)=0,t>0

(c) h(t)≠0,t<0

(d) h(t)≠0,t≤0

I got this question in an interview for internship.

The question is from Properties of the Impulse Response Representation for LTI Systems topic in portion Time Domain Representation for LTI Systems of Signals and Systems

Answer 1

Correct option is (a) h(t)=0,t<0

Easiest explanation: To the continuous system to be causal, the impulse response should satisfy the equation h(t)=0,t<0 and convolution integral is given by

y(t)=∫0^∞ h(τ)x(t-τ)dτ.