According to Bode stability criterian, a system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at frequency for which phase lag is
A. 0°
B. 45°
C. 90°
D. 180°
Answer: Option D
Related Questions on Process Control and Instrumentation
Phase lag of the frequency response of a second order system to a sinusoidal forcing function
A. Is 30°
B. Is 90° at the most
C. Approaches 180° asymptotically
D. Is 120°
Which of the following is not classified as a thermo electric pyrometer?
A. Resistance thermometer
B. Thermocouple
C. Optical pyrometer (disappearing filament type)
D. Radiation pyrometer
A. Chromel-alumel
B. Iron-constantan
C. Platinum-platinum/rhodium
D. None of these
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