Automatic Control Systems MCQ Questions & Answers

Automatic Control Systems MCQs : This section focuses on the "Automatic Control Systems". These Multiple Choice Questions (MCQs) should be practiced to improve the Automatic Control Systems skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

A lag compensator is essentially a

A. low pass filter

B. high pass filter

C. band pass filter

D. either (a) or (b)

Question 2

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

Question 3

A system has its two poles on the negative real axis and one pair of poles lies on jω axis. The system is

A. stable

B. unstable

C. limitedly stable

D. either (a) or (c)

Question 4

Assertion (A): Potentiometers can not be used as error detectors in position control systems.Reason (R): The resolution of a potentiometer places an upper limit on its accuracy

A. Both A and R are correct and R is correct explanation of A

B. Both A and R are correct but R is not correct explanation of A

C. A is correct but R is wrong

D. R is correct but A is wrong

Question 5

Bellows converts

A. pressure difference into displacement

B. pressure difference into voltage

C. displacement into pressure difference

D. either (a) or (c)

Question 6

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

Question 7

For the transport lag G(jω) = e-jωT, the magnitude is always equal to

A. 0

B. 1

C. 10

D. 0.5

Question 8

For type 2 system, the magnitude and phase angle of the term (jω)2 in the denominator, at ω = 0, are respectively

A. 0 and - 90°

B. 0 and + 90°

C. infinity and - 180°

D. infinity and + 180°

Question 9

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

Question 10

If a system is to follow arbitrary inputs accurately the bandwidth should be

A. large

B. small

C. very small

D. neither small nor large

Question 11

In a minimum phase system

A. all poles lie in the left half plane

B. all zeros lie in the left half plane

C. all poles lie in the right half plane

D. all except one pole or zero lie in the left half plane

Question 12

In an integral controller

A. the output is proportional to input

B. the rate of change of output is proportional to input

C. the output is proportional to rate of change of input

D. none of the above

Question 13

Mechanical impedance is the ratio of

A. rms force to rms velocity

B. rms force to rms displacement

C. rms velocity to rms displacement

D. none of the above

Question 14

Stepper motors find applications in

A. X-Y plotters

B. numerically controlled machining equipment

C. printers

D. all of the above

Question 15

The log magnitude curve for a constant gain K is a

A. horizontal straight line

B. horizontal straight line of magnitude 20 log K decibels

C. an inclined line having slope K

D. an inclined line having slope -K

Question 16

The phase margin and damping ratio have no relation.

A. TRUE

B. FALSE

Question 17

When a unit step voltage drives a lag network the output

A. remains constant at unit step value

B. increases exponentially from zero to final value

C. decreases exponentially from 1 to 0

D. either (b) of (c) depending on values of R and C

Question 18

Whether a linear system is stable or unstable that it

A. is a property of the system only

B. depends on the input function only

C. both (a) and (b)

D. either (a) or (b)