Electronics and Communication Engineering - Automatic Control Systems

21. 

For the second order system having following differential equation

(When θ0 and θi are output and input) the natural frequency is

A.
B.
C. KJ
D.

Answer: Option A

Explanation:

Compare with standard form.


22. 

For a second order system, the position of poles is in the shaded region shown in the given figure. The variation in damping factor is

A. from 0 to 1
B. from about 0.3 to 0.7
C. from 1 to 5
D. from 0 to 3

Answer: Option B

Explanation:

Variation in damping factor is small.


23. 

For a factor in the transfer function, the log magnitude plot

A. is a straight line with slope 0 dB/decade
B. is a straight line with slope 20 dB/decade
C. is a straight line with slope - 20 dB/decade
D. is a straight line with slope - 40 dB/decade

Answer: Option D

Explanation:

jω term in denominator gives a straight line with a slope of - 20 dB/decade and gives a straight line with a slope of - 40 dB/decade.


24. 

The frequency at which magnitude of closed loop frequency response is 3 dB below its zero frequency value is called critical frequency.

A. True
B. False

Answer: Option B

Explanation:

It is not critical frequency.


25. 

The transfer function has the characteristics of high pass filter.

A. True
B. False

Answer: Option B

Explanation:

When ω is high, the output is low.