# Control System 8

Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Control System 8

Part 2: List for questions and answers of Control System II

Q1. Find the angles of asymptotes of the open loop transfer function G(s) = k(s + 1)/s(s+2) (s+4)?

a) 90°,180°

b) 0°, 180°

c) 90°,270°

d) 60°,240°

Q2. Angle condition for complimentary root locus or inverse root locus is

a) ± (2q + 1) 180°

b) ± (2q) 180°

c) ± (2q + 1) 360°

d) ± (2q) 360°

Q3. Angle of asymptotes for complimentary root locus is

a) (2q+1)*180/(P-Z)

b) (2q+1)*180/P

c) (2q)*180/(P-Z)

d) (2q)*180/P

Q4. The characteristic equation of a control system is given below: F(s) = s4 + s3³ +3s² + 2s +5 =0. The system is

a) Stable

b) Marginally stable

c) Unstable

d) Critical stable

Q5. A unity feedback system has forward transfer function G(s) = k/((s(s+3)(s+10). The range of k for the system to be stable is

a) less than k less than 390

b) less than k less than 39

c) less than k less than 3900

d) None of the above

Q6. The open loop transfer function of a unity feedback system is given by G(s) = 1/(s+2)². The closed loop transfer function will have poles at

a) -2,-2

b) -2,-1

c) -2+j,-2-j

d) -2,2

Q7. A transfer function has its zero in the right half of the s-plane. The function

a) Is positive real

b) Is minimum phase

c) Is non-minimum phase

d) Will give stable impulse response

Q8.Electrical analogous element for damper element in mechanical translation system?

a) Capacitor

b) Inductor

c) Resistor

d) Any of the above

Q9. When deriving the transfer function of linear element

b) Initial conditions are taken into account but the element is assumed to be not loaded

c) Initial conditions are assumed to be zero but loading is taken into account

d) Initial conditions are assumed to be zero and the element is assumed to be not

Q10. Consider the function F(s) = ω /(s²+ω ²). Where F(s) = Laplace transform of f(t). The final value of f(t) is equal to

a) Zero

b) Infinite

c) Finite constant

d) A value between -1 and +1

Q11. What will be the type of the system, if the steady state performance of control system yields a non zero finite value of the velocity error constant?

a) Type – 0

b) Type – 1

c) Type – 2

d) Type – 3

Q12. A transfer function has a zero at s = -1 and poles at s = -1 ± j1. The multiplier being unity, if the input is step function, the steady state response is given by

a) 0.5 0°

b) 0.5 0°

c) 1 0°

d) 2 90°

Q13. The transfer function of the system described by d²/dt²(y(t)) + 3d/dt(y(t)) + 2y(t) = 5u(t)

with u(t) as input and y(t) as output is

a) 5/(s²+3s+2)

b) 5/s(s²+3s+2)

c) (s²+3s+2)/5

d) s(s²+3s+2)/5

Q14. Transfer function of a control system depends on

a) Initial conditions of input and output

b) System parameters alone

c) Nature of output

d) Nature of input

Q15. The poles of the second order system is at -3 ± j4. The damping ratio of the system is

a) 3/4

b) 3/7

c) 3/5

d) 4/5

Q16 The characteristic equation has the following roots for over damped stable system?

a) -2,-2

b) -2±j4

c) -2,-4

d) -2,2

Q17. The transfer function of a linear time invariant system is given as G(s) = 10/(s² + 10s + 10). The steady state value of the output of the system for step input applied at time instant t=2 sec will be

a) 0

b) 1

c) Infinity

d) Undefined

Q18. The error of a system to a ramp input is 1/5, if the type of the system is decreased by one, then the error of unit step input is

a) 0.2

b) 0.167

c) 5

d) 6/5

Q19. the closed loop transfer function of a unity feedback control system is 9/(s² + 3s + 9), then the type of the system is

a) 3

b) 0

c) 2

d) 1

Q20. The closed loop transfer function of a system is 25/(s² + 25). The settling time of the system is

a) 5 sec

b) 1 sec

c) 8 sec

d) 25 sec

Part 2: List for questions and answers of Control System II