Deck 1: Control Systems and Feedback Loops: Understanding Open and Closed Loop Systems

Question 1

In an open loop control system

A)Output is independent of control input
B)Output is dependent on control input
C)Only system parameters have effect on the control output
D)None of the above

Answer 1

Output is independent of control input

Question 2

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

A)Less expensive
B)Recalibration is not required for maintaining the required quality of the output
C)Construction is simple and maintenance easy
D)Errors are caused by disturbances

Answer 2

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

Question 3

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

A)Closed loop system
B)Semiclosed loop system
C)Open system
D)None of the above

Answer 3

Closed loop system

Question 4

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

A)decrease
B)increase
C)be unaffected
D)any of the above

Question 5

Which of the following is an open loop control system ?

A)Field controlled D.C. motor
B)Ward leonard control
C)Metadyne
D)Stroboscope

Question 6

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

A)Input command is the sole factor responsible for providing the control action
B)Presence of non-linearities causes malfunctioning
C)Less expensive
D)Generally free from problems of non-linearities

Question 7

In open loop system

A)the control action depends on the size of the system
B)the control action depends on system variables
C)the control action depends on the input signal
D)the control action is independent of the output

Question 8

has tendency to oscillate.

A)Open loop system
B)Closed loop system
C)Both a) and b)
D)Neither a) nor b)

Question 9

A good control system has all the following features except

A)good stability
B)slow response
C)good accuracy
D)sufficient power handling capacity

Question 10

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

A)Clutch
B)Eyes
C)Needle of the speedometer
D)Steering wheel

Question 11

The initial response when the output is not equal to input is called

A)Transient response
B)Error response
C)Dynamic response
D)Either of the above

Question 12

A control system working under unknown random actions is called

A)computer control system
B)digital data system
C)stochastic control system
D)adaptive control system

Question 13

An automatic toaster is a ______ loop control system.

A)open
B)closed
C)partially closed
D)any of the above

Question 14

Any externally introduced signal affecting the controlled output is called a

A)feedback
B)stimulus
C)signal
D)gain control

Question 15

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

A)Servomechanism
B)Feedback
C)Output pattern
D)Input pattern

Question 16

is a part of the human temperature control system.

A)Digestive system
B)Perspiration system
C)Ear
D)Leg movement

Question 17

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

A)Brain
B)Hands
C)Legs
D)Eyes

Question 18

is a closed loop system.

A)Auto-pilot for an aircraft
B)Direct current generator
C)Car starter
D)Electric switch

Question 19

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

A)Vernistats
B)Microsyns
C)Resolvers
D)Any of the above

Question 20

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

A)The gain of the system should be decreased
B)The gain of the system should be increased
C)The number of poles to the loop transfer function should be increased
D)The number of zeros to the loop transfer function should be increased

Question 21

increases the steady state accuracy.

A)Integrator
B)Differentiator
C)Phase lead compensator
D)Phase lag compensator

Question 22

A.C. servomotor resembles

A)two phase induction motor
B)Three phase induction motor
C)direct current series motor
D)universal motor

Question 23

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

A)Band width
B)Overall gain
C)Distortion
D)Instability

Question 24

Regenerative feedback implies feedback with

A)oscillations
B)step input
C)negative sign
D)positive sign

Question 25

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

A)reference and output
B)reference and input
C)input and feedback signal
D)output and feedback signal