Phase margin is equal to_______________?

Related Mcqs:

1. Typical specifications for design stipulates the gain margin and phase margin to be respectively__________________?

   A. > 1.7 and > 30°
   B. 30°
   C. < 1.7 and 1.7 and < 30°

2. The frequency response of a dynamic element shows a constant magnitude ratio at all frequencies. The element exhibits a negative phase shift at all frequencies. The absolute value of the phase shift increases linearly with frequency. The element has the transfer function ?

   A. e-ηS
   B. (T1S + 1)/(T2S + 1)
   C. (T1S/(T2S + 1)
   D. (T1S + 1)/(T2S

3. Gain margin is equal to the_________________?

   A. Amplitude ratio
   B. Reciprocal of amplitude ratio
   C. Gain in P controller
   D. Gain in P-I controller

4. The deflection in diaphragm (which is used as pressure sensor in pneumatic and electronic instruments) is dependent on the metal thickness, its diameter D. and shape & number of corrugations. Its deflection is proportional to_______________?

   A. d
   B. d2
   C. d3
   D. d4

5. A negative gain margin expressed in decibels means a/an ____________ system?

   A. Stable
   B. Unstable
   C. Critically damped
   D. None of these

6. The frequency response of a first order system, has a phase shift with lower and upper bounds given by________________?

   A. – ∞, π/2
   B. -π/2, π/2
   C. -π/2, 0
   D. 0, π/2

7. Phase lag of the sinusoidal response of a first order system is _________________?

   A. 120°
   B. 30°
   C. 180°
   D. 90°

8. 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°

9. A first order system with a time constant of 1 min is subjected to frequency response analysis. At an input frequency of 1 radian/min, the phase shift is______________?

   A. 45°
   B. -90°
   C. -180°
   D. -45°

10. The time constant of a unity gain, first order plus time delay process is 5 min. If the phase lag at a frequency of 0.2 rad/min is 60°, then the dead time (in minutes) is________________?

    A. 5π/12
    B. π/6
    C. π/12
    D. π/3