200 Important Single Phase Induction Motor MCQ Question & Answer | PDF Free Download
1.In various types of split phase 1- phase induction motors, the starting torques produced are in the following descending order
- ACapacitor split, resistor split, shaded pole
- BCapacitor split, shaded pole resistor split
- CResistor split, capacitor-split, shaded pole
- DShaded pole, resistor split, capacitor split
2.In hand tool applications, which one of the following single-phase motor is used?
- AShaded pole motor
- BCapacitor start motor
- CCapacitor run motor
- DAC series motor
3.A dc shunt motor does not operate on ac due to
- ALow resistance of armature circuit
- BHigh resistance of field circuit
- CHigh inductance of field circuit
- DReversal of polarity
4.A dc series motor is accidently connected to single phase ac supply. The torque produced will be
- AOf zero average value
- BOscillating
- CSteady and unidirectional
- DPulsating and unidirectional
5.A 230 V dc series motor is connected to a 230 V ac supply
- AThe motor will vibrate violently
- BThe motor will run with less efficiency and more sparking
- CThe motor will into run
- DThe fuse will be blown
6.If a dc series motor is operated on ac supply, it
- AWill not start at all
- BWill start and run but will have poor performance such as excessive sparking, poor efficiency and poor power actor
- CWill get damaged due to burning of its windings
- DWill run at excessively high speed
7.AC series motors are built with as few fields turns as possible to reduce
- AFlux
- BEddy current losses
- CReactance
- DSpeed
8.AC series motors in comparison to dc series motors do not have
- AAll parts of magnetic circuits laminated
- BMulti turn armature coils
- CVery short air gap
- DSingle turn armature coils
9.In an ac series motor, power factor is improved by
- AIncreasing the inductance of armature and field windings
- BReducing the inductance of armature and field windings
- CIncreasing the supply voltage
- DBoth (a) and (c)
10.In an ac series motor, commutation is improved by
- AReducing the number of armature conductors
- BProviding commutating poles
- CProviding commutating poles and shunting winding of each of these poles with a non-inductive resistance
- DIncreasing field winding turns
11.In ac series motors armature coils are usually connected to commutator
- AThrough resistors
- BThrough inductors
- CThrough capacitors
- DSolidly
12.A universal motor is one which has
- AConstant speed
- BConstant output
- CCapability of operating both on ac and dc with comparable performance
- DMaximum efficiency
13.A universal motor run at
- AHigher speed with dc supply and with less sparking
- BHigher speed with ac supply and with less sparking
- CSame speed with both ac and dc supplies
- DHigher speed with ac supply but with increased sparking at the brushes
14.Speed of the universal motor is
- ADependent on frequency of supply
- BProportional to frequency of supply
- CIndependent of frequency of supply
- DNone of the above
15.Direction of rotating of a universal motor can be reversed by
- AInterchanging the brush leads
- BInterchanging the supply terminals
- CEither (a) and (b)
- DNone of these
16.The speed of a universal motor is usually reduced by using
- AV-belts
- BGearing
- CChains
- DBrakes
17.Under no load operating condition, the speed of a universal motor is limited by
- Awindage and friction
- Barmature reaction
- Carmature weight
- Dsupply frequency
18.The armature reaction in a large sized universal motor is neutralized by
- AShifting the brushes
- BConnecting a compensating winding in series with the armature
- CIncreasing the number of armature coils
- DUsing low resistance brushes
19.In case of a high-speed universal motor ____ needs maximum attention
- AAir gap
- BEnd play
- CBalancing of rotor
- DInsulation of rotor
20.In universal motors, normally the ratio of width of brushes to the width of commutator segments is
- A2:1
- B1:1
- C1:2
- D4:1