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200 Important Single Phase Induction Motor MCQ Question & Answer | PDF Free Download

Single Phase Induction Motor MCQ Question and Answer PDF Free Download

1.The capacitor usually used on 1440 rpm, 50Hz capacitor start induction motor is of electrolytic type and ____capacity 

  • A10 ?F
  • B100 ?F
  • C350 ?F
  • D800 ?F
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Correct Answer : (C)

350 ?F

Explanation:

2.A capacitor selected for capacitor start induction motor should be rated for 

  • APeak voltage 
  • BRms voltage 
  • CAverage voltage 
  • DNone of these
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Correct Answer : (A)

Peak voltage 

Explanation:

3.The capacitor employed in a capacitor start induction motor has no

  • AVoltage rating 
  • BPolarity marking
  • CDielectric rating
  • DDefinite capacitance value
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Correct Answer : (B)

Polarity marking

Explanation:

The capacitor employed in a capacitor start induction motor has no Polarity marking.

4.A capacitor start single phase induction motor is used for

  • AEasy to start loads
  • BMedium start loads
  • CHard to start loads
  • DAny type of start loads
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Correct Answer : (C)

Hard to start loads

Explanation:

5.A capacitor start induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance. The motor will

  • ANot start at all
  • BStart and run slowly
  • CStart and run at rated speed
  • DStart with humming noise
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Correct Answer : (A)

Not start at all

Explanation:

6.If the capacitor of a capacitor start induction motor is short circuited the motor will

  • AStart
  • BNot Start
  • CBurn
  • DStart with jerks
Answer / Hint Save Question
Correct Answer : (B)

Not Start

Explanation:

7.If the capacitor of a capacitor start induction motor fails to open when it picks up the speed

  • AThe motor will stop 
  • BThe auxiliary winding will get damaged
  • CThe capacitor will get damaged
  • DThe main winding will get damaged 
Answer / Hint Save Question
Correct Answer : (C)

The capacitor will get damaged

Explanation:

8.Capacitor start capacitor run induction motor is basically a ____motor.

  • ATwo phases
  • BAc series 
  • CCommutator
  • DSynchronous
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Correct Answer : (A)

Two phases

Explanation:

9.Two capacitor type single phase induction motor is generally coupled with the air conditioner compressor because it

  • Ais cheaper
  • Bis quite in operation
  • Chas higher running torque 
  • Dhas low starting as well as running currents 
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Correct Answer : (D)

has low starting as well as running currents 

Explanation:

10.In a ceiling fan employing permanent capacitor motor

  • ASecondary winding surrounds the primary winding
  • BPrimary winding surrounds the secondary winding
  • CBoth are usual arrangements
  • DNone of the above
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Correct Answer : (A)

Secondary winding surrounds the primary winding

Explanation:

11.Capacitor start and capacitor run motors are used in

  • AHoists
  • BRolling mills
  • CMining
  • DRefrigerator
Answer / Hint Save Question Comment On Question
Correct Answer : (D)

Refrigerator

Explanation:

Capacitor start and capacitor run motors are used in Refrigerator. The Capacitor Start Capacitor Run Induction Motor is suitable for higher inertia loads where frequent starts are required. It is used to pumps, refrigerator, air conditioner compressors etc.

12.In a shaded pole motor, the phase splitting is achieved by placing a shagging coil at the slot cut around the

  • ALarger part of the pole
  • BSmaller part of the pole
  • CBoth the parts of the pole
  • DAny of the above 
Answer / Hint Save Question
Correct Answer : (B)

Smaller part of the pole

Explanation:

13.In a shaded pole motor, the rotating field is developed by using

  • ASalient poles
  • BA capacitor
  • CShading coils
  • DDamper winding
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Correct Answer : (C)

Shading coils

Explanation:

14.Shaded pole motor is proved with 

  • ALaminated salient poles and a squirrel cage rotor
  • BA commutator
  • CA capacitor 
  • DA centrifugal switch
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Correct Answer : (A)

Laminated salient poles and a squirrel cage rotor

Explanation:

15.In a shaded pole motor, shading coils are used to

  • Areduce winding losses
  • Breduce friction losses
  • Cproduce rotating magnetic field
  • Dprotect against sparking 
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Correct Answer : (C)

produce rotating magnetic field

Explanation:

16.In a shaded pole induction motor, locked rotor current is ____full load current 

  • Aless than
  • Bequal to 
  • Cslightly more than 
  • Dseveral times the 
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Correct Answer : (C)

slightly more than 

Explanation:

17.The direction of rotation of a shade pole induction motor

  • ACannot be reversed unless there is a provision for shifting of shading coil from one half to the other half of the pole 
  • BCan be reversed by interchanging
  • CCan be reversed by interchanging the supply terminals
  • DCan be reversed by open circuiting the shading rings 
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Correct Answer : (A)

Cannot be reversed unless there is a provision for shifting of shading coil from one half to the other half of the pole 

Explanation:

18.The speed of single-phase induction motors can be controlled by

  • AVarying the applied voltage to the stator winding 
  • BVarying the number of poles on the stator 
  • CEither (a) or (b)
  • DNone of the above 
Answer / Hint Save Question
Correct Answer : (C)

Either (a) or (b)

Explanation:

19.The wattage rating for a ceiling motor will be in the range

  • A50 to 250 W
  • B250 to 500w
  • C50 to 150 W
  • D10 to 20 W
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Correct Answer : (C)

50 to 150 W

Explanation:

20.The type of single-phase induction motor having the highest power factor at full load is

  • AShaded pole type 
  • BSplit phase type
  • CCapacitor start type capacitor run type
  • DCapacitor run type
Answer / Hint Save Question
Correct Answer : (D)

Capacitor run type

Explanation: