Control Systems MCQs with Answers 2027

Q281

Two identical first order systems have been cascaded non-interactively, the unit step response of system is:

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Q282

Match List-I with List-II and select the correct answer, using the options given below the lists:

List-I	List-II
a. Lag compensation	1. Exterior of unit Circle
b. Lead compensation	2. PD Control
c. Stability	3. Non-minimum phase
d. Instability	4. Left half of s-plane
	5. PI control

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Q283

Open question

If a zero is added in a forward path of a second order system:

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Q284

Open question

The phase margin of a system with the open-loop transfer function

G (s) H (s) = \frac{( 1 - s )}{( 1 + s ) ( 2 + s )}

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Q285

Open question

The signal flow graph of a closed-loop system is shown in the figure, where TD represents the disturbance in the forward path: The effect of the disturbance can be reduced by:
Control Systems mcq question image

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Q286

Open question

A unity feedback system has a forward path transfer function equal to

\frac{42.25}{s ( s + 6.5 )} .

The unit step response of this system starting from rest, will have its maximum value at time equal to:

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Q287

Open question

A second-order system has a transfer function given by

G (s) = \frac{25}{s ^{2} + 8 s + 25} .

If the system, initially at rest, is subjected to a unit step input at t = 0. the second peak in the response will occur at

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Q288

Open question

Given the state variable model {A, B, C} of a single-input, single-output system, the asymptotic stability is determined from:

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Q289

Open question

The transfer function

\frac{Y ( s )}{U ( s )}

of a system described by the state equations

x \cdot

(t) = -2x(t) + 2u(t) and y(t) = 0.5x(t) is

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Q290

Open question

Consider the system

\frac{d x}{d t} = A x + B u

with

A = \left[ {\begin{array}{*{20}{c}} 1&0\\ 0&1 \end{array}} \right]

and

B = [p q]

where p and q are arbitrary real numbers. Which of the following statements about the controllability of the system is true?

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Q291

Open question

Consider the following statements for a.c. series motors:
1. The rotor is designed so that its R/X ratio is small.
2. dT/dω < 0 where T and ω are torque and speed respectively.
3. The reference and control voltages should be in phase quadrature, but their magnitudes need not be equal.
Which of the statement given above are correct?

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Q292

Open question

Which one of the following is NOT a correct statement about the state-space model of a physical system?

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Q293

Open question

A certain control system is represented by the following differential equation. Its transfer function would be

\frac{d ^{2} y}{d t ^{2}} + \frac{d y}{d t} + 3 y = \frac{d x}{d t} + 2 x

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Q294

Open question

The main draw-back of a feedback system is

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Q295

Open question

Feedback control system are basically

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Q296

Open question

Which of the following rotors are used in a two-phase ac servomotor?
1. Solid iron motor
2. Squirrel cage rotor
3. Drag cup rotor
Select the correct answer using the options given below:

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Q297

Open question

A system with the transfer function

\frac{Y ( s )}{X ( s )} = \frac{s}{s + p}

has an output

y (t) = cos (2 t - \frac{π}{3})

for the input signal

x (t) = p cos (2 t - \frac{π}{2}) .

Then, the system parameter 'p' is

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Q298

Open question

In case of d.c. servomotor, the back-emf is equivalent to an "electric friction" which tends to:

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Q299

Open question

The time required for the step response to decrease and stay within a specified percentage of its final value is called:

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Q300

Open question

Despite the presence of negative feedback, control system still have problems of instability because of

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