Control System MCQs

Question 1

Microsyn is trade name for (a) potentiometer

Accepted Answer

Answer

linear transformer

Answer

(c) resolver

Answer

rotary differential transformer

Question 2

Zero initial condition of a control system signifies that

Accepted Answer

the system is at rest but stores no energy

Answer

the system is at rest but stores energy

Answer

the reference input to working system is zero

Answer

the system is working but stores no energy

Question 3

Which of the following system conveniently djsplays the impact of poles and zeros on phase margin and gain margin?

Accepted Answer

Nyquist plot

Answer

root locus

Answer

Bode plot

Answer

Routh?Hwrwitz criterion

Question 4

A system has a complex conjugate root pair of multiplicity two or more in its characteristic equation. The impulse response of the system will be

Accepted Answer

a sinusoidal oscillation with time multipper; the system is therefore unstable.

Answer

a sinusoidal oscillation which decays exponentially; the system is therefore stable.

Answer

a sinusoidal oscillation which rises exponentially with time; the system is therefore unstable.

Answer

a dc term and harmonic oscillation; the system therefore becomes limitingly stable.

Question 5

The unit step response of a second order linear system with zero initial states is given by c (t) = 1 + 1.25 exp (-6t) sin (8t - tan-1 1.333); t > 0 The damping rafio and the undamped natural frequency of oscillation of the system are respectively

Accepted Answer

0.6 and 10 rad/s

Answer

0.6 and 12.5 rad/s

Answer

0.8 and 10 rad/s

Answer

0.8 and 12.5 rad/s

Question 6

Which one of the following statements regarding the state transmition matrix is correct?

Accepted Answer

002 - ti) 4)(t1 - to) = 4)(t2 - to)

Answer

0(0) = 0

Answer

0-1 (t) = ()

Answer

4)(t1 + t2) = 4?(t1) + 0(t2)

Question 7

A control system whose step response is 0.5 (1 + e-2t) is cascaded to another control block whose impulse response is e4. The transfer function of the cascaded combination is

Accepted Answer

450

Answer

150

Answer

30?

Answer

600

Question 8

The characteristic equation of a closed loop control system is given by 52 + 9s + 16 = 0. The resonant frequency in radians/sec of the system is

Accepted Answer

4

Answer

2

Answer

2?IF

Answer

413-

Question 9

For a unit step input, a system with forward path transfer, function G(s)20= -7 and feedback path transfer function H(s) = (s + 5) has a steady state output of

Accepted Answer

0.2

Answer

20

Answer

5

Answer

zero