Electronics and Communication Engineering - Automatic Control Systems

41. 

For the control system in the given figure, the value of K for critical damping is

A. 1
B. 5.125
C. 6.831
D. 10

Answer: Option B

Explanation:

since ζ = 1, ωn = 3.5 Hence 2 + 2k = 3.52 = 12.25 or K = 5.125 .


42. 

Bode magnitude plot is drawn between

A. magnitude of network function and ω
B. dB magnitude and log ω
C. dB magnitude and ω
D. loge (magnitude) and log ω

Answer: Option B

Explanation:

Frequency is plotted on log scale and magnitude is taken in dB.


43. 

For the system in the given figure,

A.
B.
C.
D. none of the above

Answer: Option B

Explanation:

For inner loop we have transfer function =

Then = .


44. 

In the given figure, if R = XC, voltage gain is

A. 0 dB
B. 3 dB
C. -3 dB
D. 20 dB

Answer: Option C

Explanation:

If R = XC, V0 = 0.5 Vi Hence gain is -3 dB.


45. 

For the circuit in the given figure, V2(s)/V1(s) =

A.
B.
C.
D.

Answer: Option B

Explanation:

.