Electrical Engineering UPSC PYQ 2025

Answer the following sub-parts: Sketch the approximate root-locus plot for a time-delay system approximated by the transfer function

G(s) = K(1 – s/2) / [s(s + 1)(1 + s/2)].

Also compute the largest value of K for which the system is stable under unity feedback and verify this value from the root-locus plot. [10M] The signal-flow graph of a system is as shown below. Determine the overall transmission R(s)/Y(s) and evaluate the sensitivity of the output to variations in K1 at s = 10. What would be the value of sensitivity obtained under DC condition, i.e. s = 0? [10M]