Control System MCQs

Question 1

The unit-impulse response of a unit-feedback control system is given by c(t) = -te-t + 3 et, (t,0)

Accepted Answer

s2 + 5s + 7

Answer

S2 + 3s + 2

Answer

s2 + 3s + 2

Question 2

The open loop transfer function is equal to

Accepted Answer

zero

Answer

infinity

Answer

one

Answer

none of

Question 3

The maximum overshoot is s(s + 1) equal to

Accepted Answer

0.173

Answer

0.143

Answer

0.153

Answer

0.163

Question 4

None of the poles of a lonear control system lie in the right half of s-plane. For a bounded input, the output of this system

Accepted Answer

is always bounded

Answer

could be unbounded

Answer

always tends to zero

Answer

none of the above

Question 5

The phase lead compensation is used to

Accepted Answer

decrease rise time and increase overshoot

Answer

increase rise time and decrease overshoot

Answer

decrease both rise time and overshoot

Answer

increase both rise time and overshoot

Question 6

Ratio of the rotor reactance X to the rotor resistance R for a two-phase servontor

Accepted Answer

is less than that of a normal induction motor

Answer

is equal to that of a normal induction motor

Answer

is greater than that of a normal induction motor.

Answer

may be less or greater than that of a normal induction motor.

Question 7

Feedback control systems are

Accepted Answer

less sensitive to forward-path parameter changes than to feedback-path parameter changes.

Answer

insensitive to both forward-and feedback-path parameter changes.

Answer

less sensitive to feedback-path parameter changes than to forward-path parameter changes.

Answer

equally sensitive to forward-and feedback-path parameter changes.

Question 8

A unity feedback system has open-loop transfer function G(s). The steady-state error is zero for

Accepted Answer

step input and type-1 G(s)

Answer

ramp input and type-I G(s)

Answer

ste input and type-G(s)

Answer

ramp input and type-0 G(s)

Question 9

A linear time-invariant system initially at rest, when subjected to a unit-step input, gives a response y(t) = te-t, t> 0. The transfer function of the system is.

Accepted Answer

marginally stable

Answer

always stable

Answer

unstable with one pole on the right half s-plane

Answer

unstable with two poles on the right half s-plane