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GATE 2014 EC (EC3) – Question 56

Control Systems · Transient and Steady-State Analysis of LTI Systems · 2 marks · Numerical answer

Find the steady-state error of the system shown for a unit-step input.

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Correct answer: 0.49 to 0.51

Explanation

The forward DC gain is G(0)=4/2=2 and feedback gain H(0)=2/4=1/2, so loop DC gain is1. For a stable loop, E/R=1/(1+GH), giving **e∞=1/(1+1)=0.5**. This is the marked internal error r−Hc; because feedback is not unity, it differs from the tracking difference r−c.