Consider a unit feedback control system with open-loop transfer

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Consider a unit feedback control system with open-loop transfer function
G (s) = K/ [s (s + 1)].
The steady state error of the system due to a unit step input is—

1. zero
2. K
3. 1/ K
4. ∞

Correct Option: A

e_ss = _{s → 0}Lim sE(s)

= _{s → 0}Lims.	s.R(s)
	1 + (K/s(s+1))1

= H(s) = 1 and if r(t) = u(t)
then R(s) = 1/s

= _{s → 0}Lim	s(s + 1)
	s(s + 1) + K

= 0