ESE : Control Systems - National Champion Test for ESE & GATE EC Exams

Question 1

The process of imitating one system with another so that the imitating systems accepts the same data, executes same programs and achieves same results as the imitated systems is known as

Question 2

Match List- I(Components) with List- II (Function) and select the correct answer using the code given below the lists:
List-I
A) Servomotor
B) Amplidyne
C) Potentiometer
D) Flapper valve
List-II
1) Error detector
2) Transducer
3) Actuator
4) Power amplifier

Question 3

A control system whose step response is

is cascaded to another control block whose impulse response is

. What is the transfer function of the cascaded combination?

Question 4

14.4mW

Question 5

Which is the following can be used as a tachogenerator in control system?

Question 6

What is the unit impulse response of the system shown in figure for t ≥ 0?

Question 7

In a servo-system, the device used for providing derivative feedback is known as

Question 8

An electric motor is developing 10 kW at a speed of 900 rpm. The torque available at the shaft is

Question 9

The transfer from d(s) to y (s) is

Question 10

The transfer function of phase-lead compensator is given by

, where

. What is the maximum phase shift provided by this compensator.

Question 11

Match List-I (Compensation) with List-II (Characteristic) and select the correct answer using the code given below the Lists:
List-I
A) Lag
B) Lead
C) Lag- Lead
D) Rate
List-II
1) Increases bandwidth
2) Attenuation
3) Increases damping factor
4) Second order

Question 12

What is the effect of phase-lag compensation on the performance of a servo system?

Question 13

For which one of the following, given physical realization corresponds to PD controller?

Question 14

A phase lead compensating network consists of only capacitors and resistors. The locations of its pole and zero in s-plane are at P_c and Z_c respectively. Which of the following conditions must be satisfied?

Question 15

Statement(I): The phase angle plot in Bode diagram is not affected by the variation in open loop gain of the system.
Statement(II): The variation in gain of the system has no effect on the phase margin.

Question 16

The constant magnitude locus for M = 1, in G-phase is given by the following equation where

and

Question 17

For a unity feedback control system, if its open-loop transfer function is given by

then its gain margin will

Question 18

In a feedback control system, phase margin (PM) is
1) Directly proportional to

2) Inversely proportional to

3) Independent of

4) Zero when

= 0
Which of the above statements are correct?

Question 19

The gain margin in dBs of a unity feedback control system whose open-loop transfer function,

is

Question 20

In control systems, excessive bandwidth is NOT employed because

Question 21

The polar plot of frequency response of a linear under damped second order system is shown in the figure below. What is the transfer function of this system?

Question 22

At which frequency does the Bode magnitudeplot for the function

have gain crossover frequency?

Question 23

Consider the following statements in connection with frequency domain specifications of a control system:
1) Resonant peak and peak overshoot are both functions of the damping ratio

only
2) The resonant frequency

3) Higher the resonant peak, higher is the maximum overshoot of the step response.
Which of the statements given above are correct?

Question 24

Which one of the following is correct?
If the open-loop transfer functions has one pole in the right half of s-plane, the closed loop system will be stable if the Nyquist plot GH______.

Question 25

The unit step response of a system is
[1–e^-t (1+t)] u(t). What is the nature of the system in turn of stability?

Question 26

Consider the following statements : in connection with ‘the closed-loop poles of feedback control system
1) conjugate Poles on jω-axis will make the output amplitude neither decaying nor growing in time.
2) conjugate Poles on RHS will make the output amplitude growing in time.
3) conjugate Poles on RHS will make the output amplitude decaying in time.
4) conjugate Poles on LHS will make the output amplitude decaying in time.

Question 27

Consider the following statements about Routh-Hurwitz criterion:
If all the elements in one row of Routh array are zero, then there are
1) Pairs of conjugate roots on imaginary axis.
2) Pairs of equal real roots with opposite sign.
3) Conjugate roots forming a quadrate in the s-plane.

Question 28

How many roots of the following equation lie in the right-half of s-plane?
2s⁴ + s³ + 2s² + 5s + 10 = 0

Question 29

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

Question 30

The first element of each of the rows of a Routh-Hurwitz stability test showed the signs as follows

Consider the following statements:
1) The system has three roots in the right-half of s-plane.
2) The system has three roots in the left-half of s-plane.
3) The system is stable.
4) The system is unstable.
Which of the above statements about the system are correct?