According to Bode stability criterion, a system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at frequency for which phase lag is_________________?

Question

Accepted Answer

0°. Bode's criterion states instability occurs if the magnitude is greater than 1 (exceeding unity) when the phase shift is -180 degrees. However, based on the provided options and common textbook phrasing related to this specific question structure, option A (0°) might be referencing a different stability condition or there might be an error in the question/options pairing.