Question

A series RC circuit excited by voltage V is __________

(a) A memory less system

(b) A causal system

(c) A dynamic system

(d) Static system

The question was posed to me in an internship interview.

Origin of the question is Region of Convergence topic in division Laplace Transform and System Design of Signals and Systems

Answer 1

Correct choice is (c) A dynamic system

The explanation is: Dynamic systems are those systems which consist of memory. In the series RC circuit excited by voltage V, the capacitor C is an energy storing element which acts as a memory for the circuit. Therefore since system has memory it is not a memoryless system. Also, a causal system depends only on the past and present value. But since the future value of the charge is also under consideration in this type of circuit, so the system is not causal. Since charge moves about in the circuit due to the applied voltage V, hence the system is not static system. Therefore the system is a dynamic system.