Transfer Function Problem 1.1

Ask

Output of a linear time invariant control system is c(t) for a certain input r(t). If r(t) is modified by passing it through a block whose transfer function is $e^{-s}$ and then applied to the system, the modified output of the system would be

(a) $c(t-1)u(t-1)$

(b) $c(t)u(t-1)$

(c) ${c(t)\over(1+e^t)}$

(d) $c(t)\over(1+e^-t)$

Answer is ( b )

Concept

Type Reasoning here