### 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=Β±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 κ(s)κi(s) of the thermometer is given by**ππΉπͺπ+π**

**68 .** Which of the following represents the variation of temperature inclination of the thermometer with time, after the thermometer is suddenly plugged air?**κ(π)=κπ’ [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)**=ππ¬+πs2+π¬+π**represents a** stable system**.

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

**73 . ** ** Closed loop system** has tendency to oscillate.

**74 .** The limit of the gain k for which the forward pathκo(π·)πΈ(π·)=k(1+0.01D)π·(1+π·)(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:**

d2cππ‘2 + **6.4 πcππ‘ = 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.**