Question

The laplace transform of a cascaded system is defined if _______

(a) the individual systems have a common R.O.C.

(b) the individual systems doesn’t have a common R.O.C.

(c) the impulse response of each system is defined

(d) cannot be determined

I got this question during an internship interview.

I'd like to ask this question from Laplace Transform topic in division Control System Applications of MATLAB

Answer 1

Correct option is (a) the individual systems have a common R.O.C.

The explanation: It’s necessary for the individual systems, in a cascaded system, to have a common R.O.C.- otherwise the Laplace transform won’t be absolutely converging in a region. If ti doesn’t converge, the transform is not defined.