Of these statements
A. 1 and 4 are correct
B. 1 and 2 are correct
C. 1, 2 and 3 are correct
D. 2,3 and 4 are correct
Answer:D
Of these statements
A. 1 and 4 are correct B. 1 and 2 are correct C. 1, 2 and 3 are correct D. 2,3 and 4 are correct
Explanation: For unstable system the signs of gain margin and phase margin are always different or they can both be negative.