Question 1:
In a system low friction coefficient facilitates
A.
Reduced velocity lag error
B.
Increased velocity lag error
C.
Increased speed of response
D.
Reduced time constant of the system
Answer: _________
Question 2:
As a result of introduction of negative feedback which of the following will not decrease?
A.
Band width
B.
Overall gain
C.
Distortion
D.
Instability
Answer: _________
Question 3:
. . . . . . . . can be extended to systems which are time-varying?
A.
Bode-Nyquist stability methods
B.
Transfer functions
C.
Root locus design
D.
State model representatives
Answer: _________
Question 4:
The term backlash is associated with
A.
servomotors
B.
induction relays
C.
gear trains
D.
any of the above
Answer: _________
Question 5:
A closed loop system is distinguished from open loop system by which of the following ?
A.
Servomechanism
B.
Feedback
C.
Output pattern
D.
Input pattern
Answer: _________
Question 6:
Transfer function of a system is used to calculate which of the following ?
A.
The order of the system
B.
The time constant
C.
The output for any given input
D.
The steady state gain
Answer: _________
Question 7:
The second derivative input signals modify which of the following ?
A.
The time constant of the system
B.
Damping of the system
C.
The gain of the system
D.
The time constant and suppress the oscillations
Answer: _________
Question 8:
In a stable control system backlash can cause which of the following ?
A.
Underdamping
B.
Overdamping
C.
Poor stability at reduced values of open loop gain
D.
Low-level oscillations
Answer: _________
Question 9:
The transfer function is applicable to which of the following ?
A.
Linear and time-in variant systems
B.
Linear and time-variant systems
C.
Linear systems
D.
Non-linear systems
Answer: _________
Question 10:
Phase margin of a system is used to specify which of the following ?
A.
Frequency response
B.
Absolute stability
C.
Relative stability
D.
Time response
Answer: _________
Question 11:
A control system working under unknown random actions is called
A.
Computer control system
B.
Digital data system
C.
Stochastic control system
D.
Adaptive control system
Answer: _________
Question 12:
From which of the following transfer function can be obtained ?
A.
Signal flow graph
B.
Analogous table
C.
Output-input ratio
D.
Standard block system
Answer: _________
Question 13:
Which of the following devices is used for conversion of co-ordinates ?
A.
Microsyn
B.
Selsyn
C.
Synchro-resolver
D.
Synchro-transformer
Answer: _________
Question 14:
Which of the following is an open loop control system ?
A.
Field controlled D.C. motor
B.
Ward leonard control
C.
Metadyne
D.
Stroboscope
Answer: _________
Question 15:
Which of the following is exhibited by Root locus diagrams ?
A.
The poles of the transfer function for a set of parameter values
B.
The bandwidth of the system
C.
The response of a system to a step input
D.
The frequency response of a system
Answer: _________
Question 16:
Which of the following devices are commonly used as error detectors in instruments ?
A.
Vernistats
B.
Microsyns
C.
Resolvers
D.
Any of the above
Answer: _________
Question 17:
Which of the following statements is not necessarily correct for open control system ?
A.
Input command is the sole factor responsible for providing the control action
B.
Presence of non-linearities causes malfunctioning
C.
Less expensive
D.
Generally free from problems of non-linearities
Answer: _________
Question 18:
The on-off controller is a _____ system.
A.
digital
B.
linear
C.
non-linear
D.
discontinuous
Answer: _________
Question 19:
A controller, essentially, is a
A.
sensor
B.
clipper
C.
comparator
D.
amplifier
Answer: _________
Question 20:
The phase lag produced by transportation relays
A.
Is independent of frequency
B.
Is inversely proportional to frequency
C.
Increases linearly with frequency
D.
Decreases linearly with frequency
Answer: _________
Question 21:
By which of the following the control action is determined when a man walks along a path?
A.
Brain
B.
Hands
C.
Legs
D.
Eyes
Answer: _________
Question 22:
In a control system integral error compensation _______ steady state error
A.
increases
B.
minimizes
C.
does not have any effect on
D.
any of the above
Answer: _________
Question 23:
The type-2 system has ________ at the origin.
A.
No net pole
B.
Net pole
C.
Simple pole
D.
Two poles
Answer: _________
Question 24:
Which of the following should be done to make an unstable system stable ?
A.
The gain of the system should be decreased
B.
The gain of the system should be increased
C.
The number of poles to the loop transfer function should be increased
D.
The number of zeros to the loop transfer function should be increased
Answer: _________
Question 25:
With feedback _____ increases.
A.
system stability
B.
sensitivity
C.
gain
D.
effects of disturbing signals
Answer: _________
Question 26:
Which of the following is an electromagnetically device ?
A.
Induction relay
B.
Thermocouple
C.
LVDT
D.
Any of the above
Answer: _________
Question 27:
Which of the following can be measured by LVDT?
A.
Displacement
B.
Velocity
C.
Acceleration
D.
Any of the above
Answer: _________
Question 28:
The frequency and time domain are related through which of the following?
A.
Laplace Transform and Fourier Integral
B.
Laplace Transform
C.
Fourier Integral
D.
Either (B) or (C)
Answer: _________
Question 29:
Addition of zeros in transfer function causes which of the following?
A.
Lead-compensation
B.
Lag-compensation
C.
Lead-lag compensation
D.
None of the above
Answer: _________
Question 30:
In force-voltage analogy, velocity is analogous to
A.
current
B.
charge
C.
inductance
D.
capacitance
Answer: _________
Question 31:
Directly converts temperature into voltage.
A.
Thermocouple
B.
Potentiometer
C.
Gear train
D.
LVDT
Answer: _________
Question 32:
Which of the following statements is correct for a system with gain margin close to unity or a phase margin close to zero ?
A.
The system is relatively stable
B.
The system is highly stable
C.
The system is highly oscillatory
D.
None of the above
Answer: _________
Question 33:
In pneumatic control systems the control valve used as final control element converts
A.
Pressure signal to electric signal
B.
Pressure signal to position change
C.
Electric signal to pressure signal
D.
Position change to pressure signal
Answer: _________
Question 34:
When the initial conditions of a system are specified to be zero it implies that the system is
A.
At rest without any energy stored in it
B.
Working normally with reference input
C.
Working normally with zero reference input
D.
At rest but stores energy
Answer: _________
Question 35:
In order to increase the damping of a badly underdamped system which of following compensators may be used ?
A.
Phase-lead
B.
Phase-lag
C.
Both (A) and (B)
D.
Either (A) and (B)
Answer: _________
Question 36:
Static error coefficients are used as a measure of the effectiveness of closed loop systems for specified ________ input signal.
A.
acceleration
B.
velocity
C.
position
D.
all of the above
Answer: _________
Question 37:
A.C. servomotor resembles
A.
two phase induction motor
B.
Three phase induction motor
C.
direct current series motor
D.
universal motor
Answer: _________
Question 38:
The temperature, under thermal and electrical system analogy, is considered analogous to
A.
voltage
B.
current
C.
capacitance
D.
charge
Answer: _________
Question 39:
In electrical pneumatic system analogy the current is considered analogous to
A.
velocity
B.
pressure
C.
air flow
D.
air flow rate
Answer: _________
Question 40:
In liquid level and electrical system analogy, voltage is considered analogous to
A.
head
B.
liquid flow
C.
liquid flow rate
D.
none of the above
Answer: _________
Question 41:
In a stable control system saturation can cause which of the following ?
A.
Low-level oscillations
B.
High-level oscillations
C.
Conditional stability
D.
Overdamping
Answer: _________
Question 42:
Pressure error can be measured by which of the following ?
A.
Differential bellows and straingauge
B.
Selsyn
C.
Strain gauge
D.
Strain gauge and potentiometer
Answer: _________
Question 43:
Is the reference input minus the primary feedback.
A.
Manipulated variable
B.
Zero sequence
C.
Actuating signal
D.
Primary feedback
Answer: _________
Question 44:
The transfer function technique is considered as inadequate under which of the following conditions ?
A.
Systems having complexities and non-linearities
B.
Systems having stability problems
C.
Systems having multiple input disturbances
D.
All of the above
Answer: _________
Question 45:
A control system with excessive noise, is likely to suffer from
A.
saturation in amplifying stages
B.
loss of gain
C.
vibrations
D.
oscillations
Answer: _________
Question 46:
In open loop system
A.
the control action depends on the size of the system
B.
the control action depends on system variables
C.
the control action depends on the input signal
D.
the control action is independent of the output
Answer: _________
Question 47:
Velocity error constant of a system is measured when the input to the system is unit _______ function.
A.
parabolic
B.
ramp
C.
impulse
D.
step
Answer: _________
Question 48:
The transient response, with feedback system,
A.
rises slowly
B.
rises quickly
C.
decays slowly
D.
decays quickly
Answer: _________
Question 49:
The initial response when tne output is not equal to input is called
A.
Transient response
B.
Error response
C.
Dynamic response
D.
Either of the above
Answer: _________
Question 50:
Spring constant in force-voltage analogy is analogous to
A.
capacitance
B.
reciprocal of capacitance
C.
current
D.
resistance
Answer: _________
Question 51:
Which of the following statements is correct for any closed loop system ?
A.
All the co-efficients can have zero value
B.
All the co-efficients are always non-zero
C.
Only one of the static error co-efficients has a finite non-zero value
D.
None of the above
Answer: _________
Question 52:
In a system zero initial condition means that
A.
The system is at rest and no energy is stored in any of its components
B.
The system is working with zero stored energy
C.
The system is working with zero reference signal
D.
None of the above
Answer: _________
Question 53:
Any externally introduced signal affecting the controlled output is called a
A.
feedback
B.
stimulus
C.
signal
D.
gain control
Answer: _________
Question 54:
Technique gives quick transient and stability response
A.
Root locus
B.
Bode
C.
Nyquist
D.
Nichols
Answer: _________
Question 55:
A control system in which the control action is somehow dependent on the output is known as
A.
Closed loop system
B.
Semiclosed loop system
C.
Open system
D.
None of the above
Answer: _________
Question 56:
Increases the steady state accuracy.
A.
Integrator
B.
Differentiator
C.
Phase lead compensator
D.
Phase lag compensator
Answer: _________
Question 57:
If the gain of the critical damped system is increased it will behave as
A.
oscillatory
B.
critically damped
C.
overdamped
D.
underdamped
Answer: _________
Question 58:
In an automatic control system which of the following elements is not used ?
A.
Error detector
B.
Final control element
C.
Sensor
D.
Oscillator
Answer: _________
Question 59:
A car is running at a constant speed of 50 km/h, which of the following is the feedback element for the driver ?
A.
Clutch
B.
Eyes
C.
Needle of the speedometer
D.
Steering wheel
Answer: _________
Question 60:
Which of the following can be measured by the use of a tachogenerator ?
A.
Acceleration
B.
Speed
C.
Speed and acceleration
D.
Displacement
Answer: _________
Question 61:
A signal other than the reference input that tends to affect the value of controlled variable is known as
A.
Disturbance
B.
Command
C.
Control element
D.
Reference input
Answer: _________
Question 62:
The first order control system, which is well designed, has a
A.
small bandwidth
B.
negative time constant
C.
large negative transfer function pole
D.
none of the above
Answer: _________
Question 63:
A good control system has all the following features except
A.
good stability
B.
slow response
C.
good accuracy
D.
sufficient power handling capacity
Answer: _________
Question 64:
The position and velocity errors of a type-2 system are
A.
constant, constant
B.
constant, infinity
C.
zero, constant
D.
zero, zero
Answer: _________
Question 65:
With feed back _____ reduces.
A.
system stability
B.
system gain
C.
system stability and gain
D.
none of the above
Answer: _________
Question 66:
Is a closed loop system.
A.
Auto-pilot for an aircraft
B.
Direct current generator
C.
Car starter
D.
Electric switch
Answer: _________
Question 67:
The effect of error damping is to
A.
provide larger settling lime
B.
delay the response
C.
reduce steady state error
D.
any of the above
Answer: _________
Question 68:
The band width, in a feedback amplifier.
A.
remains unaffected
B.
decreases by the same amount as the gain increase
C.
increases by the sane saaaajajt as the gain decrease
D.
decreases by the same amount as the gain decrease
Answer: _________
Question 69:
In an open loop control system
A.
Output is independent of control input
B.
Output is dependent on control input
C.
Only system parameters have effect on the control output
D.
None of the above
Answer: _________
Question 70:
Due to which of the following reasons excessive bond width in control systems should be avoided ?
A.
It leads to slow speed of response
B.
It leads to low relative stability
C.
Noise is proportional to band width
D.
None of the above
Answer: _________
Question 71:
Hydraulic torque transmission system is analog of
A.
amplidyne set
B.
resistance-capacitance parallel circuit
C.
motor-generator set
D.
any of the above
Answer: _________
Question 72:
If a step function is applied to the input of a system and the output remains below a certain level for all the time, the system is
A.
not necessarily stable
B.
stable
C.
unstable
D.
always unstable
Answer: _________
Question 73:
On which of the following factors does the sensitivity of a closed loop system to gain changes and load disturbances depend ?
A.
Frequency
B.
Loop gain
C.
Forward gain
D.
All of the above
Answer: _________
Question 74:
In thermal-electrical analogy charge is considered analogous to
A.
heat flow
B.
reciprocal of heat flow
C.
reciprocal of temperature
D.
temperature
Answer: _________
Question 75:
An increase in gain, in most systems, leads to
A.
smaller damping ratio
B.
larger damping ratio
C.
constant damping ratio
D.
none of the above
Answer: _________
Question 76:
In case of type-1 system steady state acceleration is
A.
unity
B.
infinity
C.
zero
D.
10
Answer: _________
Question 77:
The transient response of a system is mainly due to
A.
inertia forces
B.
internal forces
C.
stored energy
D.
friction
Answer: _________
Question 78:
Which of the following is the best method for determining the stability and transient response ?
A.
Root locus
B.
Bode plot
C.
Nyquist plot
D.
None of the above
Answer: _________
Question 79:
A conditionally stable system exhibits poor stability at
A.
low frequencies
B.
reduced values of open loop gain
C.
increased values of open loop gain
D.
none of the above
Answer: _________
Question 80:
Is a part of the human temperature control system.
A.
Digestive system
B.
Perspiration system
C.
Ear
D.
Leg movement
Answer: _________
Question 81:
Which of the following is the non-linearity caused by servomotor ?
A.
Static friction
B.
Backlash
C.
Saturation
D.
None of the above
Answer: _________
Question 82:
The output of a feedback control system must be a function of
A.
reference and output
B.
reference and input
C.
input and feedback signal
D.
output and feedback signal
Answer: _________
Question 83:
Which of the following is the input to a controller ?
A.
Servo signal
B.
Desired variable value
C.
Error signal
D.
Sensed signal
Answer: _________
Question 84:
Which of the following is the definition of proportional band of a controller ?
A.
The range of air output as measured variable varies from maximum to minimum
B.
The range of measured variables from set value
C.
The range of measured variables through which the air output changes from maximum to minimum
D.
Any of the above
Answer: _________
Question 85:
has tendency to oscillate.
A.
Open loop system
B.
Closed loop system
C.
Both (A) and (B)
D.
Neither (A) nor (B)
Answer: _________
Question 86:
An amplidyne can give which of the following characteristics ?
A.
Constant current
B.
Constant voltage
C.
Constant current as well as constant voltage
D.
Constant current, constant voltage and constant power
Answer: _________
Question 87:
In a control system the output of the controller is given to
A.
Final control element
B.
Amplifier
C.
Comparator
D.
Sensor
Answer: _________
Question 88:
technique is not applicable to nonlinear system ?
A.
Nyquist Criterion
B.
Quasi linearization
C.
Functional analysis
D.
Phase-plane representation
Answer: _________
Question 89:
A phase lag lead network introduces in the output
A.
lag at all frequencies
B.
lag at high frequencies and lead at low frequencies
C.
lag at low frequencies and lead at high frequencies
D.
none of the above
Answer: _________
Question 90:
The capacitance, in force-current analogy, is analogous to
A.
momentum
B.
velocity
C.
displacement
D.
mass
Answer: _________
Question 91:
The viscous friction co-efficient, in force-voltage analogy, is analogous to
A.
charge
B.
resistance
C.
reciprocal of inductance
D.
reciprocal of conductance
Answer: _________
Question 92:
Mass, in force-voltage analogy, is analogous to
A.
charge
B.
current
C.
inductance
D.
resistance
Answer: _________
Question 93:
A differentiator is usually not a part of a control system because it
A.
reduces damping
B.
reduces the gain margin
C.
increases input noise
D.
increases error
Answer: _________
Question 94:
An automatic toaster is a ______ loop control system.
A.
open
B.
closed
C.
partially closed
D.
any of the above
Answer: _________
Question 95:
Is an open loop control system.
A.
Ward Leonard control
B.
Field controlled D.C. motor
C.
Stroboscope
D.
Metadyne
Answer: _________
Question 96:
For open control system which of the following statements is incorrect ?
A.
Less expensive
B.
Recalibration is not required for maintaining the required quality of the output
C.
Construction is simple and maintenance easy
D.
Errors are caused by disturbances
Answer: _________
Question 97:
A.C. servomotor is basically a
A.
universal motor
B.
single phase induction motor
C.
two phase induction motor
D.
three phase induction motor
Answer: _________
Question 98:
Regenerative feedback implies feedback with
A.
oscillations
B.
step input
C.
negative sign
D.
positive sign
Answer: _________
Question 99:
By which of the following the system response can be tested better ?
A.
Ramp input signal
B.
Sinusoidal input signal
C.
Unit impulse input signal
D.
Exponentially decaying signal
Answer: _________
Question 100:
Zero initial condition for a system means
A.
input reference signal is zero
B.
zero stored energy
C.
ne initial movement of moving parts
D.
system is at rest and no energy is stored in any of its components
Answer: _________
Question 101:
In closed loop control system, with positive value of feedback gain the overall gain of the system will
A.
decrease
B.
increase
C.
be unaffected
D.
any of the above
Answer: _________
Question 102:
Is not a final control element.
A.
Control valve
B.
Potentiometer
C.
Electropneumatic converter
D.
Servomotor
Answer: _________
Question 103:
Signal will become zero when the feedback signal and reference signs are equal.
A.
Input
B.
Actuating
C.
Feedback
D.
Reference
Answer: _________
Answer Key
1:
A
2:
A
3:
D
4:
C
5:
B
6:
C
7:
D
8:
D
9:
A
10:
C
11:
C
12:
A
13:
C
14:
A
15:
A
16:
D
17:
B
18:
C
19:
C
20:
C
21:
D
22:
B
23:
D
24:
B
25:
A
26:
C
27:
D
28:
A
29:
A
Solution: Addition of zeros in transfer function causes lead-compensation. Lead-compensation is achieved by adding zeros to the transfer function, which advances the phase of the system and improves the transient response. In a lead-compensated system, the zero increases the system's responsiveness by increasing the phase margin, leading to a faster response. Lag-compensation and lead-lag compensation involve different configurations of poles and zeros to achieve specific performance characteristics.
30:
A
31:
A
32:
C
33:
B
34:
A
Solution: Zero initial condition for a system means system is at rest and no energy is stored in any of its components.
35:
A
36:
D
37:
A
38:
A
39:
D
40:
A
41:
C
42:
A
43:
C
44:
D
45:
A
46:
D
47:
B
48:
D
49:
A
50:
B
51:
C
52:
A
53:
B
Solution: Any externally introduced signal affecting the controlled output is referred to as a stimulus . In the context of control systems and feedback control, a stimulus is an external input or disturbance that can influence the behavior of the system. This stimulus can lead to changes in the system's output, and the control system aims to minimize the effects of such disturbances through feedback and control actions. The other options are related terms but do not specifically refer to externally introduced signals: Option A: feedback refers to the process of taking a portion of the output and feeding it back to the input of a system to regulate its behavior. Option C: signal is a general term for a function representing information or data, which can include control signals, stimuli, or any other data-carrying function. Option D: gain control is related to adjusting the amplification or gain of a signal within a control system but is not the term used to describe externally introduced signals. So, the correct answer is Option B: stimulus .
54:
A
55:
A
56:
A
57:
D
58:
D
59:
C
60:
B
61:
A
62:
C
63:
B
Solution: A good control system should ideally have the following features: Good stability: Ensures that the system maintains its performance and does not exhibit excessive oscillations or instability. Good accuracy: Ensures that the system accurately follows the desired input or reference signal. Sufficient power handling capacity: Ensures that the system can handle the required load without performance degradation. However, a slow response is not desirable in a good control system. A good control system should exhibit a fast response time to quickly react to changes and provide timely corrections. Thus, Option B (slow response) is the feature that does not align with the characteristics of a good control system.
64:
C
Solution: The position and velocity error of the type 2 system is zero and a constant value as for type 2 system velocity error is finite while acceleration error is infinite.
65:
B
66:
A
67:
C
68:
C
69:
A
Solution: An open-loop system is defined by the fact that the output signal or condition is neither measured nor fed back for comparison with the input signal or system set point. Therefore open-loop systems are commonly referred to as “Non-feedback systems”.
70:
C
71:
C
72:
A
73:
D
74:
D
75:
A
76:
B
77:
C
78:
A
79:
B
80:
B
81:
C
82:
A
83:
C
Solution: Error signal is the input to the controller and it causes the output to be the desired output.
84:
C
85:
B
86:
D
87:
A
88:
A
89:
C
90:
D
91:
B
92:
C
93:
C
94:
A
95:
B
96:
B
Solution: For an open control system, the following statements are generally true: Less expensive: Open control systems are often less expensive to implement compared to closed-loop systems. Construction is simple and maintenance easy: Open control systems are simpler in design and therefore easier to maintain. Errors are caused by disturbances: Open control systems can be affected by external disturbances as they do not have feedback to correct deviations. However, the statement that recalibration is not required for maintaining the required quality of the output is incorrect. Open control systems may still require recalibration to maintain output quality, as they lack feedback mechanisms to automatically adjust for changes and disturbances.
97:
C
98:
D
99:
C
100:
D
101:
A
102:
B
103:
B