StreakPeaked· Practice

ExamsGATETechnical

In the Nyquist plot of the open-loop transfer function G(s)H(s) = (3s + 5)/(s - 1) corresponding to the feedback loop shown in the figure, the infinite semi-circular arc of the Nyquist contour in s-plane is mapped into a point at

  1. G(s)H(s) = ∞
  2. G(s)H(s) = 0
  3. G(s)H(s) = 3
  4. G(s)H(s) = -5

Correct answer: G(s)H(s) = 3

Solution

The infinite semicircular arc maps to the value of G(s)H(s) as s approaches infinity: lim (3s+5)/(s-1) = 3. So the arc maps to G(s)H(s)=3, which is option 2, not the stored option 1.

Related GATE Technical questions

⚔️ Practice GATE Technical free + battle 1v1 →