Electronics and Communication Engineering - Automatic Control Systems

11. 

For the given figure C(s)/R(s)

A.
B.
C.
D.

Answer: Option B

Explanation:

.


12. 

A stepper motor is

A. a two phase induction motor
B. is a kind of rotating amplifier
C. is an electromagnetic transducer used to convert an angular position of shaft into electrical signal
D. is an electromechanical device which actuates a train of step angular movements in response to a train of input pulses on one to one basis

Answer: Option D

Explanation:

When input pulses are applied, the motor moves in steps.


13. 

In a two phase ac servomotor rotor resistance is R and rotor reactance is X. The speed curve will be linear if

A.
B.
C.
D. X2 = R

Answer: Option A

Explanation:

In a two phase servomotor ∠ < 1 so that torque speed curve is almost linear.


14. 

In the given figure, the input frequency is such that R = XC. Then

A. v0 lags vi by 45°
B. v0 lags vi by 90°
C. v0 leads vi by 45°
D. v0 leads vi by 90°

Answer: Option A

Explanation:

R = XC, voltage drops across R and XC are equal and at 90° with respect by each other. V0 lags Vi by 45°.


15. 

From the noise point of view, bandwidth should

A. be large
B. not be too large
C. should be as large as possible
D. should be infinite

Answer: Option B

Explanation:

If noise is to be eliminated, bandwidth cannot be large.