08 - Pole Zero Analysis

For a physically realizable system, the order of the numerator of transfer function must be less than or equal to that of the denominator. e.g.: \[\begin{aligned} {3} G_1(s) &= \frac{(s+1)(s+2)(s+3)}{(s+4)(s+5)} \qquad& \text{(Physically unrealizable)} \\ G_1(s) &= \frac{(s+1)(s+2)}{(s+4)(s+5)} & \text{(Physically realizable)} \end{aligned}\]