Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

An ON OFF controller is a

A. P controller
B. integral controller
C. non-linear controller
D. PID controller
Answer» D. PID controller
2.

An effect of phase-lag compensation on servo system performance is that

A. for a given relative stability, the velocity constant is increased
B. for a given relative stability, the velocity constant is decreased
C. the bandwidth of the system is increased
D. the time response is made faster
Answer» B. for a given relative stability, the velocity constant is decreased
3.

The minimum number of states necessary to describe the network shown in the figure in a state variable form is

A. 2
B. 3
C. 4
D. 6
Answer» C. 4
4.

Given a unity feedback system with open-loop transfer function.

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» B. Fig:- B
5.

The polar plot of a type-1, 3-pole, open-loop system is shown in figure. The closedloop system is

A. always stable
B. marginally stable
C. unstable with one pole on the right half s-plane
D. unstable with two poles on the right half s-plane
Answer» D. unstable with two poles on the right half s-plane
6.

A linear discrete-time system has the characteristic equation, z

A. is stable
B. is marginally stable
C. is unstable
D. stability cannot be assessed from the given information.
Answer» B. is marginally stable
7.

Which of the following is the transfer function of a system having the Nyquist plot in figure below?

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K</center></td></tr><tr><td style="text-align: center;">s(s + 2)<sup>2</sup>(s + 5)</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup>(s + 2)(s + 5)</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup>(s + 2)(s + 5)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 1)(s + 3)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup>(s + 2)(s + 5)</td></tr></table>
Answer» C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup>(s + 2)(s + 5)</td></tr></table>
8.

A system is described by X = [] 0 1 2 3 X + [] 0 1 u y = [1 0] X The system is

A. controllable and observable
B. uncontrollable and observable
C. controllable and unobservable
D. uncontrollable and unobservable
Answer» B. uncontrollable and observable
9.

A lag compensation network

A. All
B. (i) and (ii)
C. (ii), (iii) and (iv)
D. (iii) and (ii)
Answer» B. (i) and (ii)
10.

The log-magnitude plot of a system is given below.

A. integrator
B. PID controller
C. PD controller
D. proportional controller
Answer» C. PD controller
11.

Which one of the following is an example of open-loop system?

A. A windscreen wiper
B. Respiratory system of an animal
C. A system for controlling anti-rocket missiles.
D. None of these
Answer» B. Respiratory system of an animal
12.

A plant has the following transfer function:

A. 20 sec
B. 40 sec
C. 35 sec
D. 45 sec
Answer» C. 35 sec
13.

Consider the vectors drawn form the poles and zeros at j = 1 on the imaginary axis as shown in the given figure. The transfer function G (j1) is given by

A. 1/2 0
B. 2.7 31
C. 2 45
D. 2 67.4
Answer» B. 2.7 31
14.

In the following pick out the time-invariant systems.

A. (i) and (iii)
B. (i) and (ii)
C. (ii) and (iii)
D. (i) only
Answer» B. (i) and (ii)
15.

In the following, pick out the non-linear systems

A. (i) and (iii)
B. (ii) and (iii)
C. (i) and (ii)
D. None of these
Answer» B. (ii) and (iii)
16.

The transfer function of a phase lead controller is (1 + 3Ts)/ (1 + Ts). The maximum value of phase provided by this controller is

A. 90
B. 60
C. 45
D. 30
Answer» E.
17.

In a synchronous error detector, the output voltage is proportional to [ (t)]n where (t) is the rotor velocity and n equals to

A. 2
B. 1
C. 1
D. 2
Answer» D. 2
18.

If stability error for step input and speed of response be the criterion for design, what controller would you recommend?

A. P controller
B. PD controller
C. PI controller
D. PID controller
Answer» E.
19.

In the following, pick out the linear systems.

A. (i) and (ii)
B. (i) only
C. (i) and (iii)
D. (ii) and (iii)
Answer» D. (ii) and (iii)
20.

In the Bode-plot of a unit feedback control system, the value of phase of G (j ) at the gain crossover frequency is 125 . The phase margin of the system is

A. 125
B. 55
C. 55
D. 125
Answer» D. 125
21.

The block diagram shown below is equivalent to

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» C. Fig:- C
22.

A second order system with no zeros has its poles located at 3 + j4 and 3 j4 in the s-plane. The undamped natural frequency and the damping factor of the system are respectively

A. 4 rad/sec and 0.75
B. 3 rad/sec and 0.60
C. 5 rad/sec and 0.80
D. 5 rad/sec and 0.60
Answer» B. 3 rad/sec and 0.60
23.

The transfer function is 1 + 0 5s/1 + s. It represents a

A. lead network
B. lag network
C. lag-lead network
D. proportional controller
Answer» C. lag-lead network
24.

For a gain constant K, the phase-lead compensator

A. reduces the slope of the magnitude curve in the entire range of frequency domain
B. decreases the gain cross-over frequency
C. reduce the phase margin
D. reduces the resonance peak, M
E. <sub>p</sub>
Answer» B. decreases the gain cross-over frequency
25.

Which input yields natural response?

A. ac input
B. dc input
C. impulse input
D. a ramp input
Answer» D. a ramp input
26.

The type of a transfer function denotes the number of

A. Poles at origin
B. Zeros at origin
C. Finite poles
D. Poles at infinity
Answer» B. Zeros at origin
27.

Sinusoidal oscillator are

A. stable
B. marginally stable
C. unstable
D. conditionally stable
Answer» C. unstable
28.

A minimum-phase system with no zeros has a phase angle of 270 at gain crossover frequency. The system is

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» C. marginally stable
29.

G (s) =1s(1 + 6s)

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» D. conditionally stable
30.

A linear second-order system with the transfer function

A. 16%
B. 9%
C. 2%
D. zero
Answer» D. zero
31.

When two identical first order systems have been cascaded non-interactively. The unit step response of the systems will be

A. overdamped
B. underdamped
C. undamped
D. critically damped
Answer» E.
32.

The transfer function of the system

A. Stable
B. Unstable
C. Conditionally stable
D. Marginally stable
Answer» C. Conditionally stable
33.

It is given that

A. 2 and 3
B. 3 and 2
C. 3 and 3
D. 2 and 2
Answer» C. 3 and 3