Quiznetik

Control Systems | 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 raining 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 tne 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. Which of the following devices are commonly used as error detectors in instruments ?

Correct : D. any of the above

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

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

20. increases the steady state accuracy.

Correct : A. integrator

21. A.C. servomotor resembles

Correct : A. two phase induction motor

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

Correct : A. band width

23. Regenerative feedback implies feedback with

Correct : D. positive sign

24. is an open loop control system.

Correct : B. field controlled d.c. motor

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

Correct : A. saturation in amplifying stages

26. Zero initial condition for a system means

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

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

Correct : C. the output for any given input

28. The band width, in a feedback amplifier.

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

29. load disturbances depend ?

Correct : D. all of the above

30. The transient response, with feedback system,

Correct : D. decays quickly

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

Correct : D. the time constant and suppress the oscillations

32. 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

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

Correct : C. noise is proportional to band width

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

Correct : D. low-level oscillations

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

Correct : D. oscillator

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

Correct : A. final control element

37. A controller, essentially, is a

Correct : C. comparator

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

Correct : D. mass

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

Correct : A. voltage

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

Correct : D. air flow rate

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

Correct : A. head

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

Correct : B. resistance

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

Correct : A. current

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

Correct : D. temperature

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

Correct : C. inductance

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

Correct : C. stored energy

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

Correct : B. actuating

48. as

Correct : A. disturbance

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

Correct : A. linear and time-in variant systems

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

Correct : A. signal flow graph

51. is the reference input minus the primary feedback.

Correct : C. actuating signal

52. With feedback _____ increases.

Correct : A. system stability

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

Correct : C. unit impulse input signal

54. In a system low friction co-efficient facilitates

Correct : A. reduced velocity lag error

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

Correct : B. reciprocal of capacitance

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

Correct : A. laplace transform and fourier integral

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

Correct : A. smaller damping ratio

58. specified ________ input signal.

Correct : D. all of the above

59. A conditionally stable system exhibits poor stability at

Correct : B. reduced values of open loop gain

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

Correct : A. no pole

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

Correct : C. simple pole

62. The type 2 system has ______ at the origin.

Correct : D. two poles

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

Correct : C. zero, constant

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

Correct : B. ramp

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

Correct : B. infinity

66. 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

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

Correct : A. root locus

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

Correct : C. relative stability

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

Correct : B. lag-compensation

70. technique is not applicable to nonlinear system ?

Correct : A. nyquist criterion

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

Correct : A. phase-lead

72. The phase lag produced by transportation relays

Correct : C. increases linearly with frequency

73. Which of the following can be measured by the use of a tachogenerator ?

Correct : B. speed

74. is not a final control element.

Correct : B. potentiometer

75. 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 changes from maximum to minimum

76. In pneumatic control systems the control valve used as final control element converts

Correct : B. pressure signal to position change

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

Correct : A. differential bellows and straingauge

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

Correct : C. synchro-resolver

79. The effect of error damping is to

Correct : C. reduce steady state error

80. technique gives quick transient and stability response

Correct : A. root locus

81. A phase lag lead network introduces in the output

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

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

Correct : C. saturation

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

Correct : D. state model representatives

84. 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

85. Which of the following is an electromagnetically device ?

Correct : C. lvdt

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

Correct : C. increases input noise

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

Correct : D. underdamped

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

Correct : B. minimizes

89. An amplidyne can give which of the following characteristics ?

Correct : D. constant current, constant voltage and constant power

90. Which of the following can be measured by LVDT?

Correct : D. any of the above