Question

The transfer function for a P-D controller is

A. Kc(1+τD s)

B. Kc(1 +1/τD s)

C. Kc τD s

D. Kc/τD s

Answer: Option A

Answer 1

I believe the correct answer is Option A )Kc(1+τD s): 

Because: The proportional derivative controller is used to improve the stability of control system lacking affecting the continued state error.