GATE 2023 IN – Question 25
The number of times the Nyquist plot of $G(s)H(s)=\dfrac12\dfrac{(s-1)(s-2)}{(s+1)(s+2)}$ encircles the origin is ______.
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Correct answer: 2 to 2
Explanation
The transfer function has two right-half-plane zeros (+1,+2) and no right-half-plane poles. Applying the argument principle to the standard right-half-plane Nyquist contour gives two clockwise encirclements of the origin. The unsigned count is **2**.