Explore topic-wise MCQs in Electrical Engineering.

This section includes 166 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

If the gain of the critical damped system is increased it will behave as

A. oscillatory
B. critically damped
C. overdamped
D. underdamped
Answer» E.
52.

Amplifier:

A. armature controlled fhp dc motor
B. a pair of synchronous transmitter and control transformer
C. tach generator
D. amplidyne
Answer» E.
53.

Servomotor:

A. armature controlled fhp dc motor
B. a pair of synchronous transmitter and control transformer
C. tach generator
D. amplidyne
Answer» C. tach generator
54.

For two-phase AC servomotor, if the rotor’s resistance and reactance are respectively R and X, its length and diameter are respectively L and D then,

A. x/r and l/d are both small
B. x/r is large but l/d is small
C. x/r is small but l/d is large
D. x/r and l/d are both large
Answer» D. x/r and l/d are both large
55.

When human being tries to approach an object, his brain acts as,

A. an error measuring device
B. a controller
C. an actuator
D. an amplifier
Answer» C. an actuator
56.

Error detector:

A. armature controlled fhp dc motor
B. a pair of synchronous transmitter and control transformer
C. tach generator
D. amplidyne
Answer» B. a pair of synchronous transmitter and control transformer
57.

State space analysis is applicable for non- linear systems and for multiple input and output systems.

A. true
B. false
Answer» B. false
58.

System transformation on function H(z) for a discrete time LTI system expressed in state variable form with zero initial condition

A. -1b+d
B. c(zi-a)-1
C. (zi-a)-1z
D. (zi-a)-1
Answer» B. c(zi-a)-1
59.

When the number of poles is equal to the number of zeroes, how many branches of root locus tends towards infinity?

A. 1
B. 2
C. equal to number of zeroes
Answer» D.
60.

The addition of open loop zero pulls the root loci towards:

A. the left and therefore system becomes more stable
B. the right and therefore system becomes unstable
C. imaginary axis and therefore system becomes marginally stable
D. the left and therefore system becomes unstable
Answer» B. the right and therefore system becomes unstable
61.

If root loci plots of a particular control system do not intersect the imaginary axis at any point, then the gain margin of the system will be:

A. 0
B. 0.707
C. 1
D. infinite
Answer» E.
62.

If the gain of the system is reduced to a zero value, the roots of the system in the s- plane,

A. coincide with zero
B. move away from zero
C. move away from poles
D. coincide with the poles
Answer» E.
63.

Which one of the following are correct? The root locus is the path of the roots of the characteristic equation traced out in the s- plane?

A. as the input of the system is changed
B. as the output of the system is changed
C. as a system parameter is changed
D. as the sensitivity is changed
Answer» D. as the sensitivity is changed
64.

What is the number of the root locus segments which do not terminate on zeroes?

A. the number of poles
B. the number of zeroes
C. the difference between the number of poles and zeroes
D. the sum of the number of poles and the number of the zeroes
Answer» D. the sum of the number of poles and the number of the zeroes
65.

The breakaway point calculated mathematically must always lie on the root locus.

A. true
B. false
Answer» B. false
66.

Which one of the following is not the property of root loci?

A. the root locus is symmetrical about imaginary axis
B. they start from the open loop poles and terminate at the open loop zeroes
C. the breakaway points are determined from dk/ds = 0
D. segments of the real axis are the part of the root locus if and only is the total number of real poles and zeroes to their right is odd.
Answer» B. they start from the open loop poles and terminate at the open loop zeroes
67.

Consider the loop transfer function K(s+6)/(s+3)(s+5) In the root locus diagram the centroid will be located at:

A. -4
B. -1
C. -2
D. -3
Answer» D. -3
68.

Which one of the following applications software’s is used to obtain an accurate root locus for?

A. lisp
B. matlab
C. dbase
D. oracle
Answer» C. dbase
69.

Number of roots of characteristic equation is equal to the number of

A. branches
B. root
C. stem
D. poles
Answer» B. root
70.

Consider the following statements regarding root loci:

A. all root loci start from the respective poles of g(s) h(s)
B. all root loci end at the respective zeros of g(s) h(s) or go to infinity
C. the root loci are symmetrical about the imaginary axis of the s-plane
D. all root loci start and end from the respective poles of g(s) h(s) or go to infinity
Answer» C. the root loci are symmetrical about the imaginary axis of the s-plane
71.

Routh Hurwitz criterion is better than root locus.

A. true
B. false
Answer» C.
72.

Root locus is used to calculate:

A. marginal stability
B. absolute stability
C. conditional stability
D. relative stability
Answer» E.
73.

The addition of open loop poles pulls the root locus towards:

A. the right and system becomes unstable
B. imaginary axis and system becomes marginally stable
C. the left and system becomes unstable
D. the right and system becomes unstable
Answer» E.
74.

While increasing the value of gain K, the system becomes

A. less stable
B. more stable
C. unstable
D. absolute stable
Answer» B. more stable
75.

The main objective of drawing root locus plot is :

A. to obtain a clear picture about the open loop poles and zeroes of the system
B. to obtain a clear picture about the transient response of feedback system for various values of open loop gain k
C. to determine sufficient condition for the value of ‘k’ that will make the feedback system unstable
D. both b and c
Answer» E.
76.

Root locus of s(s+2)+K(s+4) =0 is a circle. What are the coordinates of the center of this circle?

A. -2,0
B. -3,0
C. -4,0
D. -5,0
Answer» D. -5,0
77.

                       is a quantitative measure of how fast the transients die out in the system.

A. absolutely stable
B. conditionally stable
C. unstable
D. relative stability
Answer» E.
78.

A linear system can be classified as :

A. absolutely stable
B. conditionally stable
C. unstable
D. all of the mentioned
Answer» E.
79.

Roots on the imaginary axis makes the system :

A. stable
B. unstable
C. marginally stable
D. linear
Answer» D. linear
80.

Roots with higher multiplicity on the imaginary axis makes the system :

A. absolutely stable
B. unstable
C. linear
D. stable
Answer» C. linear
81.

If the roots of the have negative real parts then the response is

A. stable
B. unstable
C. marginally stable
D. bounded
Answer» E.
82.

The roots of the transfer function do not have any effect on the stability of the system.

A. true
B. false
Answer» C.
83.

For non-linear systems stability cannot be determined due to:

A. possible existence of multiple equilibrium states
B. no correspondence between bounded input and bounded output stability and asymptotic stability
C. output may be bounded for the particular bounded input but may not be bounded for the bounded inputs
D. all of the mentioned
Answer» E.
84.

Bounded input and Bounded output stability notion concerns with :

A. a system under influence of input
B. a system not under influence of input
C. a system under influence of output
D. a system not under influence of output
Answer» B. a system not under influence of input
85.

Lag compensator reduces

A. position constant
B. velocity constant
C. position variable
D. acceleration constant
Answer» C. position variable
86.

Lead compensator increases bandwidth

A. true
B. false
Answer» B. false
87.

Proportional controller

A. decreases steady state error and improves stability
B. rise time decreases
C. transient response becomes poorer
D. increases steady state error
Answer» E.
88.

PI controller:

A. decreases steady state error and improves stability
B. rise time decreases
C. transient response becomes poorer
D. increases steady state error
Answer» D. increases steady state error
89.

PID controller:

A. decreases steady state error and improves stability
B. rise time decreases
C. transient response becomes poorer
D. increases steady state error
Answer» B. rise time decreases
90.

Which of the following is an effect of lag compensation?

A. decrease bandwidth
B. improves transient response
C. increases the effect of noise
D. increases stability margin
Answer» B. improves transient response
91.

PD controller:

A. decreases steady state error and improves stability
B. rise time decreases
C. transient response becomes poorer
D. increases steady state error
Answer» C. transient response becomes poorer
92.

An all-pass network imparts only

A. negative phase to the input
B. positive phase to the input
C. 90 degree phase shift to the input
D. 180 degree phase shift to the input
Answer» E.
93.

The roots of the characteristic equation of the second order system in which real and imaginary part represents the :

A. damped frequency and damping
B. damping and damped frequency
C. natural frequency and damping ratio
D. damping ratio and natural frequency
Answer» C. natural frequency and damping ratio
94.

Nichol’s chart is useful for the detailed study and analysis of:

A. closed loop frequency response
B. open loop frequency response
C. close loop and open loop frequency responses
D. open loop and close loop frequency responses
Answer» B. open loop frequency response
95.

The critical value of gain for a system is 40 and gain margin is 6dB. The system is operating at a gain of:

A. 20
B. 40
C. 80 d) 120
Answer» B. 40
96.

OLTF contains one zero in right half of s- plane then

A. open loop system is unstable
B. close loop system is unstable
C. close loop system is unstable for higher gain
D. close loop system is stable
Answer» D. close loop system is stable
97.

Which one of the following statements is correct? Nichol’s chart is useful for the detailed study analysis of:

A. closed loop frequency response
B. open loop frequency response
C. close loop and open loop frequency responses
D. none of the above
Answer» B. open loop frequency response
98.

Frequency range of bode magnitude and phases are decided by :

A. the lowest and higher important frequencies of dominant factors of the oltf
B. the lowest and highest important frequencies of all the factors of the open loop transfer function
C. resonant frequencies of the second factors
D. none of the above
Answer» E.
99.

4 DESIGN OF COMPENSATORS USING BODE PLOT

A. -1 and origin
B. origin and +1 c) -0.5 and 0.5
C. d) -1 and +1
Answer» B. origin and +1 c) -0.5 and 0.5
100.

What is the value of M for the constant M circle represented by the equation 8x2+18x+8y2+9=0?

A. 0.5
B. 2
C. 3
D. 8
Answer» D. 8