Quiznetik

Control System | Set 1

1. In an open loop control system

Correct : A. Output is independent of control input

2. For open control system which of the following statements is incorrect ?

Correct : B. Recalibration is not required for maintaining the required quality of the output

3. A control system in which the control action is somehow dependent on the output is known as

Correct : A. Closed loop system

4. In closed loop control system, with positive value of feedback gain the overall gain of the system will

Correct : A. decrease

5. Which of the following is an open loop control system ?

Correct : A. Field controlled D.C. motor

6. Which of the following statements is not necessarily correct for open control system ?

Correct : B. Presence of non-linearities causes malfunctioning

7. In open loop system

Correct : D. the control action is independent of the output

8. has tendency to oscillate.

Correct : B. Closed loop system

9. A good control system has all the following features except

Correct : B. slow response

10. A car is running at a constant speed of 50 km/h, which of the following is the feedback element for the driver ?

Correct : C. Needle of the speedometer

11. The initial response when the output is not equal to input is called

Correct : A. Transient response

12. A control system working under unknown random actions is called

Correct : C. stochastic control system

13. An automatic toaster is a ______ loop control system.

Correct : A. open

14. Any externally introduced signal affecting the controlled output is called a

Correct : B. stimulus

15. A closed loop system is distinguished from open loop system by which of the following ?

Correct : B. Feedback

16. is a part of the human temperature control system.

Correct : B. Perspiration system

17. By which of the following the control action is determined when a man walks along a path ?

Correct : D. Eyes

18. is a closed loop system.

Correct : A. Auto-pilot for an aircraft

19. Which of the following devices are commonly used as error detectors in instruments ?

Correct : D. Any of the above

20. Which of the following should be done to make an unstable system stable ?

Correct : B. The gain of the system should be increased

21. increases the steady state accuracy.

Correct : A. Integrator

22. A.C. servomotor resembles

Correct : A. two phase induction motor

23. As a result of introduction of negative feedback which of the following will not decrease ?

Correct : A. Band width

24. Regenerative feedback implies feedback with

Correct : D. positive sign

25. The output of a feedback control system must be a function of

Correct : A. reference and output

26. is an open loop control system.

Correct : B. Field controlled D.C. motor

27. A control system with excessive noise, is likely to suffer from

Correct : A. saturation in amplifying stages

28. Zero initial condition for a system means

Correct : D. system is at rest and no energy is stored in any of its components

29. Transfer function of a system is used to calculate which of the following ?

Correct : C. The output for any given input

30. The band width, in a feedback amplifier.

Correct : C. increases by the sane saaaajajt as the gain decrease

31. On which of the following factors does the sensitivity of a closed loop system to gain changes and load disturbances depend ?

Correct : D. All of the above

32. The transient response, with feedback system,

Correct : D. decays quickly

33. The second derivative input signals modify which of the following ?

Correct : D. The time constant and suppress the oscillations

34. Which of the following statements is correct for any closed loop system ?

Correct : C. Only one of the static error co-efficients has a finite non-zero value

35. Which of the following statements is correct for a system with gain margin close to unity or a phase margin close to zero ?

Correct : C. The system is highly oscillatory

36. Due to which of the following reasons excessive bond width in control systems should be avoided ?

Correct : C. Noise is proportional to band width

37. In a stable control system backlash can cause which of the following ?

Correct : D. Low-level oscillations

38. In an automatic control system which of the following elements is not used ?

Correct : D. Oscillator

39. In a control system the output of the controller is given to

Correct : A. final control element

40. A controller, essentially, is a

Correct : C. comparator

41. The capacitance, in force-current analogy, is analogous to

Correct : D. mass

42. The temperature, under thermal and electrical system analogy, is considered analogous to

Correct : A. voltage

43. In electrical-pneumatic system analogy the current is considered analogous to

Correct : D. air flow rate

44. In liquid level and electrical system analogy, voltage is considered analogous to

Correct : A. head

45. The viscous friction co-efficient, in force-voltage analogy, is analogous to

Correct : B. resistance

46. In force-voltage analogy, velocity is analogous to

Correct : A. current

47. In thermal-electrical analogy charge is considered analogous to

Correct : D. temperature

48. Mass, in force-voltage analogy, is analogous to

Correct : C. inductance

49. The transient response of a system is mainly due to

Correct : C. stored energy

50. signal will become zero when the feedback signal and reference signs are equal.

Correct : B. Actuating

51. A signal other than the reference input that tends to affect the value of controlled variable is known as

Correct : A. disturbance

52. The transfer function is applicable to which of the following ?

Correct : A. Linear and time-in variant systems

53. From which of the following transfer function can be obtained ?

Correct : A. Signal flow graph

54. is the reference input minus the primary feedback.

Correct : C. Actuating signal

55. With feedback _____ increases.

Correct : A. system stability

56. By which of the following the system response can be tested better ?

Correct : C. Unit impulse input signal

57. In a system zero initial condition means that

Correct : A. The system is at rest and no energy is stored in any of its components

58. In a system low friction co-efficient facilitates

Correct : A. reduced velocity lag error

59. Spring constant in force-voltage analogy is analogous to

Correct : B. reciprocal of capacitance

60. The frequency and time domain are related through which of the following?

Correct : A. Laplace Transform and Fourier Integral

61. An increase in gain, in most systems, leads to

Correct : A. smaller damping ratio

62. Static error co-efficients are used as a measure of the effectiveness of closed loop systems for specified ________ input signal.

Correct : D. all of the above

63. A conditionally stable system exhibits poor stability at

Correct : B. reduced values of open loop gain

64. The type 0 system has ______ at the origin.

Correct : A. no pole

65. The type 1 system has ______ at the origin.

Correct : C. simple pole

66. The type 2 system has at the origin.

Correct : D. two poles

67. The position and velocity errors of a type-2 system are

Correct : C. zero, constant

68. Velocity error constant of a system is measured when the input to the system is unit _______ function.

Correct : B. ramp

69. In case of type-1 system steady state acceleration is

Correct : B. infinity

70. 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

Correct : A. not necessarily stable

71. Which of the following is the best method for determining the stability and transient response ?

Correct : A. Root locus

72. Phase margin of a system is used to specify which of the following ?

Correct : C. Relative stability

73. Addition of zeros in transfer function causes which of the following ?

Correct : B. Lag-compensation

74. technique is not applicable to nonlinear system ?

Correct : A. Nyquist Criterion

75. In order to increase the damping of a badly underdamped system which of following compensators may be used ?

Correct : A. Phase-lead

76. The phase lag produced by transportation relays

Correct : C. increases linearly with frequency

77. In a stable control system saturation can cause which of the following ?

Correct : A. Low-level oscillations

78. Which of the following can be measured by the use of a tacho-generator ?

Correct : B. Speed

79. is not a final control element.

Correct : B. Potentiometer

80. Which of the following is the definition of proportional band of a controller ?

Correct : C. The range of measured variables through which the air output chan¬ges from maximum to minimum

81. Pressure error can be measured by which of the following ?

Correct : A. Differential bellows and straingauge

82. Which of the following devices is used for conversion of co-ordinates ?

Correct : C. Synchro-resolver

83. The effect of error damping is to

Correct : C. reduce steady state error

84. technique gives quick transient and stability response

Correct : A. Root locus

85. A phase lag lead network introduces in the output

Correct : C. lag at low frequencies and lead at high frequencies

86. Which of the following is the non-linearity caused by servomotor ?

Correct : C. Saturation

87. can be extended to systems which are time-varying ?

Correct : D. State model representatives

88. When the initial conditions of a system are specified to be zero it implies that the system is

Correct : D. at rest but stores energy

89. A differentiator is usually not a part of a control system because it

Correct : C. increases input noise

90. In a control system integral error compensation _______ steady state error

Correct : B. minimizes

91. Which of the following can be measured byLVDT?

Correct : D. Any of the above

92. directly converts temperature into voltage.

Correct : A. Thermocouple

93. The transfer function technique is considered as inadequate under which of the following conditions ?

Correct : D. All of the above

94. Which of the following is the output of a thermocouple ?

Correct : D. D.C. voltage

95. A.C. servomotor is basically a

Correct : C. two phase induction motor

96. The first order control system, which is well designed, has a

Correct : C. large negative transfer function pole