### Control Systems Objectives Part 04

61 . Routh Hurwitz criterion gives roots in right half of s-plane.

62 . The number of roots with positive real part for the polynomial s3+s2-2 is one.
Question 63 to 64 refer to data given below:
Considered the polynomial s4+8s3+24s2+32s+K

63 . The positive value of K for which the above polynomial has roots with zero real parts is 80.

64 . These roots are s=±j2.

65 . A system in which the control action is dependent upon the output is known as closed loop system.
Question 66 to 68 refer to Fig. 23.

66 . The thermometer can be considered to have thermal capacitance which stores heat & thermal resistance R which limits the heat flow (both A&B).

67 . The transfer function Ꝋ(s)Ꝋi(s) of the thermometer is given by𝟏𝑹𝑪𝒔+𝟏

68 . Which of the following represents the variation of temperature inclination of the thermometer with time, after the thermometer is suddenly plugged air?Ꝋ(𝐭)=Ꝋ𝐢 [1-e-t/RC]

69 . The transfer function of a system is used to calculate output for a given input.

70 . Which of the following statements is not necessarily correct for open loop control system? Presence of non-linearities causes malfunctioning.

71 . The transfer functionP(s)=𝟐𝐬+𝟏s2+𝐬+𝟏represents a stable system.

72 . Human eye can be considered as a closed loop system with multivariable feed-back.

73 . Closed loop system has tendency to oscillate.

74 . The limit of the gain k for which the forward pathꝊo(𝐷)𝐸(𝐷)=k(1+0.01D)𝐷(1+𝐷)(0.1+0.2D))
Will results in stable system is 6.4.

75 . In an open loop system, the control action is independent of the output.

76 . Open loop system is most sensitive to the presence of non-linearities.
Questions 77 and 78 refer to the data given below:
A feedback control system is represented by the following differential equation:
d2c𝑑𝑡2 + 6.4 𝑑c𝑑𝑡 = 160 eWhere e=r-0.4c, where e is output variable.

77. The value of damping ratio is 0.4.

78 . Which of the following information can be concluded about the transient behavior of the system? 25% maximum overshoot to step command.

79 . The transient response of a system is mainly due to stored energy.

80 . The main application of transfer function is in the study of steady as well as transient behaviors of systems.