1.A good control system has all the following features except

good stability

slow response

good accuracy

sufficient power handling capacity

ANSWER : : slow responseExplanation :

2.In open loop system

the control action depends on the size of the system

the control action depends on system variables

the control action depends on the input signal

the control action is independent of the output

ANSWER : : the control action is independent of the outputExplanation :

3.The initial response when tne output is not equal to input is called

Transient response

Error response

Dynamic response

Either of the above

ANSWER : : Transient responseExplanation :

4.For open control system which of the following statements is incorrect ?

Less expensive

Recalibration is not required for maintaining the required quality of the output

Construction is simple and maintenance easy

Errors are caused by disturbances

ANSWER : : Recalibration is not required for maintaining the required quality of the output6.Which of the following is an open loop control system ?

Field controlled D.C. motor

Ward leonard control

Metadyne

Stroboscope

ANSWER : : Field controlled D.C. motorExplanation :

7.A control system in which the control action is somehow dependent on the output is known as

Closed loop system

Semiclosed loop system

Open system

None of the above

ANSWER : : Closed loop systemExplanation :

8.The output of a feedback control system must be a function of

reference and output

reference and input

input and feedback signal

output and feedback signal

ANSWER : : reference and outputExplanation :

9.A control system working under unknown random actions is called

computer control system

digital data system

stochastic control system

adaptive control system

ANSWER : : stochastic control systemExplanation :

10.Regenerative feedback implies feedback with

oscillations

step input

negative sign

positive sign

ANSWER : : positive signExplanation :

5.Which of the following statements is not necessarily correct for open control system ?

Input command is the sole factor responsible for providing the control action

Presence of non-linearities causes malfunctioning

Less expensive

Generally free from problems of non-linearities

ANSWER : : Presence of non-linearities causes malfunctioningExplanation :

11.By which of the following the control action is determined when a man walks along a path ?

Brain

Hands

Legs

Eyes

ANSWER : : EyesExplanation :

12.A closed loop system is distinguished from open loop system by which of the following ?

Servomechanism

Feedback

Output pattern

Input pattern

ANSWER : : FeedbackExplanation :

13.In closed loop control system, with positive value of feedback gain the overall gain of the system will

decrease

increase

be unaffected

any of the above

ANSWER : : decreaseExplanation :

14.Which of the following should be done to make an unstable system stable ?

The gain of the system should be decreased

The gain of the system should be increased

The number of poles to the loop transfer function should be increased

The number of zeros to the loop transfer function should be increased

ANSWER : : The gain of the system should be increasedExplanation :

15.An automatic toaster is a ______ loop control system.

open

closed

partially closed

any of the above

ANSWER : : openExplanation :

16.Which of the following devices are commonly used as error detectors in instruments ?

Vernistats

Microsyns

Resolvers

Any of the above

ANSWER : : Any of the aboveExplanation :

17.Any externally introduced signal affecting the controlled output is called a

feedback

stimulus

signal

gain control

ANSWER : : stimulusExplanation :

18.As a result of introduction of negative feedback which of the following will not decrease ?

Band width

Overall gain

Distortion

Instability

ANSWER : : Band widthExplanation :

19.A.C. servomotor resembles

two phase induction motor

Three phase induction motor

direct current series motor

universal motor

ANSWER : : two phase induction motorExplanation :

20.A car is rtyining at a constant speed of 50 km/h, which of the following is the feedback element for the driver ?

Clutch

Eyes

Needle of the speedometer

Steering wheel

ANSWER : : Needle of the speedometer

1.In electrical-pneumatic system analogy the current is considered analogous to

velocity

pressure

air flow

air flow rate

ANSWER : : air flow rateExplanation :

2.Mass, in force-voltage analogy, is analogous to

charge

current

inductance

resistance

ANSWER : : inductanceExplanation :

3.A control system with excessive noise, is likely to suffer from

saturation in amplifying stages

loss of gain

vibrations

oscillations

ANSWER : : saturation in amplifying stagesExplanation :

4.Which of the following statements is correct for any closed loop system ?

All the co-efficients can have zero value

All the co-efficients are always non-zero

Only one of the static error co-efficients has a finite non-zero value

None of the above

ANSWER : : Only one of the static error co-efficients has a finite non-zero valueExplanation :

5.Due to which of the following reasons excessive bond width in control systems should be avoided ?

It leads to slow speed of response

It leads to low relative stability

Noise is proportional to band width

None of the above

ANSWER : : Noise is proportional to band widthExplanation :

6.Which of the following statements is correct for a system with gain margin close to unity or a phase margin close to zero ?

The system is relatively stable

The system is highly stable

The system is highly oscillatory

None of the above

ANSWER : : The system is highly oscillatoryExplanation :

7.The transient response of a system is mainly due to

inertia forces

internal forces

stored energy

friction

ANSWER : : stored energyExplanation :

8.The temperature, under thermal and electrical system analogy, is considered analogous to

voltage

current

capacitance

charge

ANSWER : : voltageExplanation :

9.The band width, in a feedback amplifier.

remains unaffected

decreases by the same amount as the gain increase

increases by the sane saaaajajt as the gain decrease

decreases by the same amount as the gain decrease

ANSWER : : increases by the sane saaaajajt as the gain decreaseExplanation :

10.Zero initial condition for a system means

input reference signal is zero

zero stored energy

ne initial movement of moving parts

system is at rest and no energy is stored in any of its components

ANSWER : : system is at rest and no energy is stored in any of its componentsExplanation :

11.In force-voltage analogy, velocity is analogous to

current

charge

inductance

capacitance

ANSWER : : currentExplanation :

12.On which of the following factors does the sensitivity of a closed loop system to gain changes and load disturbances depend ?

Frequency

Loop gain

Forward gain

All of the above

ANSWER : : All of the aboveExplanation :

13.In liquid level and electrical system analogy, voltage is considered analogous to

head

liquid flow

liquid flow rate

none of the above

ANSWER : : headExplanation :

14.Transfer function of a system is used to calculate which of the following ?

The order of the system

The time constant

The output for any given input

The steady state gain

ANSWER : : The output for any given inputExplanation :

15.The transient response, with feedback system,

rises slowly

rises quickly

decays slowly

decays quickly

ANSWER : : decays quickly

http://exam2win.com/electrical-engineering/control-systems/part2/questions-answers-5.jspExplanation :

16.A controller, essentially, is a

sensor

clipper

comparator

amplifier

ANSWER : : comparatorExplanation :

17.In an automatic control system which of the following elements is not used ?

Error detector

Final control element

Sensor

Oscillator

ANSWER : : OscillatorExplanation :

18.The capacitance, in force-current analogy, is analogous to

momentum

velocity

displacement

mass

ANSWER : : massExplanation :

19.In thermal-electrical analogy charge is considered analogous to

heat flow

reciprocal of heat flow

reciprocal of temperature

temperature

ANSWER : : temperatureExplanation :

20.The second derivative input signals modify which of the following ?

The time constant of the system

Damping of the system

The gain of the system

The time constant and suppress the oscillations

ANSWER : : The time constant and suppress the oscillationsExplanation :

21.The viscous friction co-efficient, in force-voltage analogy, is analogous to

charge

resistance

reciprocal of inductance

reciprocal of conductance

ANSWER : : resistanceExplanation :

22.In a stable control system backlash can cause which of the following ?

Underdamping

Overdamping

Poor stability at reduced values of open loop gain

Low-level oscillations

ANSWER : : Low-level oscillationsExplanation :

23.In a control system the output of the controller is given to

final control element

amplifier

comparator

sensor

ANSWER : : final control elementExplanation :