PTT1
Abhinav Education Society College Of Polytechnic Wadwadi Bhor (Subject : Control System and PLC
PTT1)
Marks: 20 Time:1 hr
1.Transfer function of a system is defined as the ratio of output to input in
a) Z-transformer
b) Fourier transform
c) Laplace transform
d) All of these
Answer: c
2. The principle of homogeneity and superposition are applied to:
a) Linear time invariant systems
b) Nonlinear time invariant systems
c) Linear time variant systems
d) Nonlinear time invariant systems
Answer: c
3. In regenerating (positive) the feedback, the transfer function is given by
a) C(s)/R(s)=G(s)/1+G(s)H(s)
b) C(s)/R(s)=G(s)H(s)/1-G(s)H(s)
c) C(s)/R(s)=G(s)/1+G(s)H(s)
d) C(s)/R(s)=G(s)/1-G(s)H(s)
Answer: d
4. Which principle does the linear system follow?
a) Principle of energy conservation
b) Principle of mass conservation
c) Principle of electromagnetism
d) Principle of superposition
Answer: d
5. If the blocks in block diagram reduction are in feedback then what will be equation
a) G/G+1
b) GH/1+GH
c) G/1+G.H
d) none of above
Answer: c
6. Consider the following statements with respect to the feedback of the control systems:1. Feedback
can improve stability or be harmful to stability if it is not properly applied.2. Feedback can always
improve stability3. In many situations the feedback can reduce the effect of noise and disturbance on
system performance.4. In general the sensitivity of the system gain of a feedback system of a parameter
variation depends on where the parameter is located.
a) 1,2 and 3 only
b) 1,3 and 4 only
c) 1,2 and 4 only
d) 1,2,3 and 4 only
Answer: b
7.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: c
8.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: a
9.The type 0 system has ______ at the origin.
a) no pole
b) net pole
c) simple pole
d) two poles
Answer: a
10. A control system in which the control action is somehow dependent on the output is known as
a) Closed loop system
b) Semi closed loop system
c) Open system
d) None of the above
Answer: a
11. A linear time variant system called as ______if it generates oscillations with constant amplitude and
frequency for bounded input
a) Critically Stable
b) Stable
c) Unstable
d) none of above
Answer: a
12. Time required for the response to reach 50% of the final value is called as_____
a) Settling time
b) Delay time
c) Rise time
d) Peak time
Answer: b
13. For undamped system the value of Zeta should be___
a) Zeta =0
b) Zeta <0
c) Zeta >0
d) none of above
Answer: a
14. G(S) = S(S+2)/S(S+4)(S+5) find out poles and zeros
a) Zeros 0,1 Poles 4,6,10
b) Zeros 0,5 Poles 4,6,8
c) Zeros 0,2 Poles 0,4,5
d) Zeros 1,2 Poles 0,6,7
Answer: c
15. What will be the nature of time response if the roots of the characteristic equation are located on
the s-plane imaginary axis?
a) Oscillations
b) Damped oscillations
c) No oscillations
d) Under damped oscillations
Answer: c
16. The system in which parameters changes with time called as _____________
a) Linear time invariant
b) Linear time variant
c) Linear systems
d) none of above
Answer: b
17. Laplace transform of unit step input signal is ______
a) 1/s
b) 1/s^2
c) 1/s^3
d) 1
Answer: a
18. ________ of a system is defined as the ratio of Laplace transform of the output to the Laplace
transform of input considering all initial conditions _____
a) Fourier transform, one
b) Laplace transform, non zero
c) Laplace transform , zero
d) Z transform, zero
Answer: c
19. The transfer function of RC circuit is given by_____
a) 1/sc
b) 1/ SR
c) 1/ SCR
d) R(s)/G(s)
Answer: c
20.The part of the response that remains after transient have died out is called as__________.
a) Transient Response
b) time variant response
Steady state response
d) none of above
Answer: c
.
Abhinav Education Society College Of Engineering and Technology( Polytechnic)
Sub: Control System and PLC Subject Code-22512
Marks:20 Time: 1 hr
1.. Transfer function of a system is defined as the ratio of output to input in
a) Z-transformer
b) Fourier transform
c) Laplace transform
d) All of these
Answer: c
2.In an open loop system
a) Output control the input signal
b) Output has no control over input signal
c) Some other variable control the input signal
d) Neither output nor any other variable has any effect on input
Answer: a
3.Transfer function of a system can used to study its
a) Steady state behavior
b) Transient behavior
c) Both (a) and (b)
d) None of these
Answer: c
4.The output of the feedback control system must be a function of:
a) Reference input
b) Reference output
c) Output and feedback signal
d) Input and feedback signal
Answer: d
5.The principle of homogeneity and superposition are applied to:
a) Linear time invariant systems
b) Nonlinear time invariant systems
c) Linear time variant systems
d) Nonlinear time invariant systems
Answer: c
6.In regenerating(positive) the feedback, the transfer function is given by
a) C(s)/R(s)=G(s)/1+G(s)H(s)
b) C(s)/R(s)=G(s)H(s)/1-G(s)H(s)
c) C(s)/R(s)=G(s)/1+G(s)H(s)
d) C(s)/R(s)=G(s)/1-G(s)H(s)
Answer: d
7. Benefits of feedback
a) Performance of system is greater.
b) Need for system much larger path gain and system instability.
c) Controlled variable accurately follows the desired value
d) Unaffected by parameter variations
Answer: d
8.The closed system has higher ________ than open loop control system, this implies increased
speed of response.
a) Gain
b) Bandwidth
c) Frequency
d) Speed
Answer: b
9. Feedback can always reduce the effects of noise and disturbance on system performance?
a) True
b) False
Answer: a
10.Multiple signals as input can be used in which systems:
a) Feedback systems
b) Non feedback systems
c) Feed forward systems
d) None of the mentioned
Answer: a
11. For the block diagram given in the following figure, the expression of C/R is:
a) G1G2G3/1-G2G1
b) G1G2/1-G1G2G3
c) G1G2G3/1-G1G2G3
d) G1G2/G3(1-G1G2)
Answer: a
12.The advantage of block diagram representation is that it is possible to evaluate the
contribution of each component to the overall performance of the system.
a) True
b) False
Answer: a
13.The overall transfer function from block diagram reduction for cascaded blocks is :
a) Sum of individual gain
b) Product of individual gain
c) Difference of individual gain
d) Division of individual gain
Answer: b
14 Transfer function of the system is defined as the ratio of Laplace output to Laplace input
considering initial conditions________ :
a) 1
b) 2
c) 0
d) infinite
Answer: c
15.. Feedback control systems are referred to as closed loop systems.
a) True
b) False
Answer: a
16.. Which principle does the linear system follow?
a) Principle of energy conservation
b) Principle of mass conservation
c) Principle of electromagnetism
d) Principle of superposition
b) False
Answer: d
17.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: c
18.In open loop control system Feedback not present
a.true
b. false
Answer: a
19.If the blocks in block diagram reduction are in feedback then what will be equation
1.G/G+1
2. GH/1+GH
3. G/1+G.H
4. none of above
Answer: a
20.The overall transfer function of two blocks in parallel are :
a) Sum of individual gain
b) Product of individual gain
c) Difference of individual gain
d) Division of individual gain
Answer: a
Abhinav Education Society College Of Engineering and Technology( Polytechnic)
Sub: Control System and PLC Subject
Code-
Marks:20 Time: 1 hr
1.An automatic toaster is a ______ loop control system.
(a) open
(b) closed
(c) partially closed
(d) any of the above
Answer: a
2. What is the algebraic sum of the reference input and feedback?
a) Error Signal
b) Error Detector
c) Controlled system
d) Controlled output
Answer: a
3.What is the effect of feedback in the overall gain of the system?
a) Increases
b) Decreases
c) Zero
d) No change
Answer: b
4. Effect of feedback on sensitivity is minimum in:
a) Open loop control system
b) Closed loop control system
c) None of the mentioned
d) Both of the mentioned
Answer: a
5. Feedback control systems are:
a) Insensitive to both forward and feedback path parameter changes
b) Less sensitive to feedback path parameter changes than to forward path parameter changes
c) Less sensitive to forward path parameter changes that to feedback path parameter changes
d) Equally sensitive to forward feedback path parameter changes
Answer: c
6. Consider the following statements with respect to the feedback of the control systems:1.
Feedback can improve stability or be harmful to stability if it is not properly applied.2. Feedback
can always improve stability3. In many situations the feedback can reduce the effect of noise
and disturbance on system performance.4. In general the sensitivity of the system gain of a
feedback system of a parameter variation depends on where the parameter is located.
a) 1,2 and 3 only
b) 1,3 and 4 only
c) 1,2 and 4 only
d) 1,2,3 and 4 only
Answer: b
7. The closed system has higher ________ than open loop control system, this implies increased
speed of response.
a) Gain
b) Bandwidth
c) Frequency
d) Speed
Answer: b
8. Feedback can always reduce the effects of noise and disturbance on system performance?
a) True
b) False
Answer: a
9. Feedback can cause a system that is originally stable to become___________
a) Stable
b) Unstable
c) Conditionally stable
d) Either more stable or unstable
Answer: d
10.First order system is defined as :
a) Number of poles at origin
b) Order of the differential equation
c) Total number of poles of equation
d) Total number of poles and order of equation
Answer: d
11.Laplace transform of unit impulse signal is :
a) A/s
b) A
c) 1
d) 1/s
Answer: c
12. Transient response analysis is done for_________ systems.
a) Unstable
b) Stable
c) Conditionally stable
d) Marginally stable
Answer: b
13. Standard test signals in control system are:
a) Impulse signal
b) Ramp signal
c) Unit step signal
d) All of the mentioned
Answer: d
14.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: c
15.In a control system the output of the controller is given to
(a) final control element
(b) amplifier
(c) comparator
(d) sensor
(e) none of the above
Answer: a
16.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: a
17.The type 0 system has ______ at the origin.
(a) no pole
(b) net pole
(c) simple pole
(d) two poles
Answer: a
18.The type 1 system has ______ at the origin.
(a) no pole
(b) one pole
(c) net pole
(d) two poles
Answer: b
19.In a control system the use of negative feedback
A.. Eliminates the chances of instability
B. Increases the reliability
C. Reduces the effects of disturbance and noise signals in the forward path
D. Increases the influence of variations of component parametres on the system performance
ion 1
Answer: c
20.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: b
21. A control system in which the control action is somehow dependent on the output is
known as
A. Closed loop system
B. Semi closed loop system
C. Open system
D. None of the above
22.In a control system an error detector
A. Detects the error and signal out an alarm
B. Detects the errors of the system
C. Produces an error signal as the actual difference of value and desired value of output
D. Any of the above
.
.
