Multiple Choice Questions with answers on Control Systems
1.
Which terminology deals with the excitation or
stimulus applied to the system from an external source for the generation of an
output?
a) Input signal
b)
Output signal
c)
Error signal
d)
Feedback signal
2.
Which among the following is not an advantage of
an open loop system?
a)
Simplicity in construction & design
b)
Easy maintenance
c)
Rare problems of stability
d) Requirement of system recalibration from
time to time
3.
Which among the following represents an illustration
of closed loop system?
a)
Automatic washing machine
b) Automatic electric iron
c)
Bread toaster
d)
Electric hand drier
4.
How an output is represented in the control
systems?
a)
r(t)
b) c(t)
c)
C. x(t)
d)
d.y(t)
5.
The output is said to be zero state response
because conditions are made equal to zero.
a) Initial
b)
Final
c)
Steady state
d)
Impulse response
6.
Basically, poles of transfer function are the
laplace transform variable values which causes the transfer function to become
___________
a)
Zero
b)
Unity
c) Infinite
d)
Average value
7.
By equating the denominator of transfer function
to zero, which among the following will be obtained?
a) Poles
b)
Zeros
c)
Both a and b
d)
None of the above
8.
The output signal is fed back at the input side
from the _________point
a)
Summing
b)
Differential
c) Take-off
d)
All of
the above
9.
In a parallel combination, the direction of flow
of signals through blocks in parallel must resemble to the main
a) Forward
b)
Feedback
c)
Opposite
d)
Diagonal
10.
While shifting a take-off point after the
summing point, which among the following should be added?
a) Summing point ¡n series with take-off point
b)
Summing point in parallel with take-off point
c)
Block of reciprocal transfer function
d)
Block of inverse transfer function
11.
In a signal flow graph, nodes are represented by
small
a) Circles
b)
Squares
c)
Arrows
d)
Pointers
12.
According to signal flow graph, which among the
following represents the relationship between nodes by drawing a line between
them?
a) Branch
b)
Self-loop
c)
Semi-node
d)
Mesh
13.
Which type of node comprises incoming as well as
outgoing branches?
a)
Source node
b)
Sink node
c) Chain node
d)
Main node
14.
According to the property of impulse test
signal, what is the value of an impulse at t = O?
a)
Zero
b)
Unity
c) Infinite
d)
Unpredictable
15.
What is the value of parabolic input in Laplace
domain?
a)
1
b)
A/s
c)
A/s2
d) A/s3
16.
Which among the following is/are an/the
illustration/s of a sinusoidal input?
a)
Setting the temperature of an air conditioner
b)
Input given to an elevator
c) Checking the quality of speakers of music
system
d)
All of the above
17.
If a system is subjected to step input, which
type of static error coefficient performs the function of controlling steady
state error?
a) Position
b)
Velocity
c)
Acceleration
d)
Retardation
18.
On the basis of an output response, into how
many parts can the s-plane be divided?
a)
2
b) 3
c)
4
d)
6
19.
If the complex conjugate poles are located at
RHP, what would be the nature of corresponding impulse response?
a)
Exponential
b)
Damping oscillations
c) Increasing amplifier
d)
Constant amplitude oscillations
20.
Which among the following are solely responsible
in determining the speed of response of control system?
a) Poles
b)
Zeros
c)
Speed of input
d)
All of the above
21.
If a pole is located at s = -5 ¡n left-hand
plane (LHP), how will ¡t be represented in Laplace domain?
a) 1/s+5
b)
1/s—5
c)
s/ s + 5
d)
s/s—5
22.
In second order system, which among the
following remains independent of gain (k)?
a) Open loop poles
b)
Closed loop poles
c)
C. Both a and b
d)
None of the above
23.
Root locus specifies the movement of closed loop
poles especially when the gain of system ________
a)
Remains constant
b) Exhibit variations
c)
Gives zero feedback
d)
Gives infinite poles
24.
Which condition ¡s used to verify the existence
of a particular point on the root locus?
a)
Amplitude
b)
Frequency
c)
Magnitude
d) Angle
25.
While specifying the angle and magnitude
conditions, angles are added whereas magnitudes get ________
a)
Subtracted
b) Multiplied
c)
Divided
d)
All of the above
26.
The magnitude & phase relationship between input
and the steady state output is called as
frequency domain.
a)
Step
b)
Ramp
c) Sinusoidal
d)
Parabolic
27.
Which unit ¡s adopted for magnitude measurement
¡n Bode plots?
a)
Degree
b)
Decimal
c) Decibel
d)
Deviation
28.
In an octave frequency band, the ratio of f2 I
f1 ¡s equivalent to ________
a) 2
b)
4
c)
8
d)
10
29.
In polar plots, what does each and every point
represent w.r.t magnitude and angle?
a)
Scalar
b)
Vector
c) Phasor
d)
Differentiator
30.
In polar plots, ¡f a pole ¡s added at the
origin, what would be the value of the magnitude at C) = O?
a)
Zero
b) Infinity
c)
Unity
d)
Unpredictable
31.
Conventional control theory is applicable to
______ systems
a) SISO
b)
MIMO
c)
Time varying
d)
Non-linear
32.
State space analysis ¡s applicable even ¡f the
initial conditions are
a)
Zero
b) Non-zero
c)
C. Equal
d)
Not equal
33.
If an error signal e(t) of an ON-OFF controller
is found to be greater than zero, what would be its output?
a)
10%
b)
50%
c)
80%
d) 100%
34.
Which time ¡s responsible for introducing an
error ¡n the temperature regulation of applications associated with ON OFF controllers?
a)
Rise time
b) Dead time
c)
Switching time
d)
Decay time
35.
Which controller has the potential to
eliminate/overcome the drawback of offset in proportional controllers?
a) P-l
b)
P-D
c)
Both a and b
d)
None of the above
36.
In P-l controller, what does an integral of a
function compute?
a)
Density of curve
b) Area under the curve
c)
Volume over the curve
d)
Circumference of curve
37.
Which among the following controls the speed of
D.C. motor?
a)
Galvanometer
b)
Gauss meter
c)
Potentiometer
d) Tachometer
38.
Into which energy signal does the position
sensor convert the measured position of servomotor in servomechanisms?
a)
Mechanical
b) Electrical
c)
Thermal
d)
Light
39.
What is the value of steady state error in
closed loop control systems?
a) Zero
b)
Unity
c)
Infinity
d)
Unpredictable
40.
A good control system should be sensitive to
a)
Internal disturbances
b)
Environmental parameters
c)
Parametric variations
d) Input signals (except noise)
41.
Which point on the root locus specifies the meeting
or collision of two poles?
a)
Centroid
b) Break away point
c)
Stability point
d)
Anti-break point
42.
If a signal is passed through an integrator, it
_____the amplitude of noise signal.
a)
Enhances
b) Reduces
c)
Stabilizes
d)
Factorizes