Control System MCQs

Question 1

Saturation in a stable control system may cause

Accepted Answer

conditional stability

Answer

overdamping

Answer

low level oscillations

Answer

high level oscillations

Question 2

Noise in a control system can be kept low by

Accepted Answer

reducing the bandwidth

Answer

attenuating such frequencies at which external signals get coupled into the system

Answer

both A and B above

Answer

none of the above

Question 3

Excessive noise in a control system may result in

Accepted Answer

reduction in gain

Answer

reduction in bandwidth

Answer

oscillations

Answer

saturation in amplifying stages

Question 4

For a closed loop system to be stable, the Nyquist plot of G (s) H (s) must encircle the point (-1, j0) as many time as the number of

Accepted Answer

zeros of G(s) H(s) in the RHS of s-plane

Answer

zeros of G(s) H(s) in the LHS of s-plane

Answer

poles of G(s) H(s) in the RHS of s-plane

Answer

poles of G(s) H(s) in the LHS of s-plane

Question 5

The function G(s) H(s) of a system has no poles in the RHS of s-plane. For the system to be stable, the Nyquist plot of G(s) must not enclose the

Accepted Answer

point (? 1, j0)

Answer

origin

Answer

point (? 1, ? jl)

Answer

point (1, j0)

Question 6

Polar plots for positive and negative frequencies

Accepted Answer

are always symmetrical

Answer

can never be symmetrical

Answer

may or may not be symmetrical

Answer

none of these

Question 7

The actuating signal in a control system is always fed to

Accepted Answer

the control element

Answer

the controlled element

Answer

the feedback element

Answer

all of these

Question 8

The Op Amp control components in a control system ideally draw

Accepted Answer

zero current

Answer

medium current

Answer

small current

Answer

very small current

Question 9

Which of the following system provides good performance if offset is to be avoided?

Accepted Answer

proportional plus integral action

Answer

proportional action

Answer

proportional plus differential action

Answer

proportional plus integral action plus differential action