Single Phase Induction Motors MCQs

1.What is absent in the capacitors utilized in single-phase capacitor motors?

2.What will happen if a DC series motor is powered by an AC source?

It will produce excessive sparkingIts efficiency will decrease significantlyIt will exhibit a low power factorAll of the above effects will occur

3.What defines a universal motor?

It can function on both DC and AC power sources with nearly the same speed and performance.It is designed for global sales and distribution.It operates at unsafe high speeds when running without load.

4.In an AC series motor, how are the armature coils typically connected to the commutator?

Via resistorsVia inductive reactancesVia capacitive elementsDirectly without any components

5.Which component is found in a repulsion motor?

Slip ringsCommutatorBoth slip rings and commutatorNeither slip rings nor commutator

6.Which type of motor contains two distinct windings within its design?

7.Identify the incorrect statement about a reluctance motor from the options below:

It typically cannot be reversed during normal operation.Its operation does not depend on D.C. field excitation.It essentially functions as a single-phase synchronous-induction motor with salient poles.The squirrel cage rotor has an asymmetrical magnetic design to alter the reluctance path between the rotor and stator.

8.Which of the following components is absent in a shaded pole motor?

a centrifugal switcha capacitora commutatorall of these components

9.How should you change the rotation direction of a capacitor start motor while it is operating?

Turn off the power and wait for the motor to stop, then restore power after swapping the connections of either the main or auxiliary winding.Cut off the power and immediately turn it back on after reversing the main winding connections.Change the auxiliary winding connections but only reconnect it after the motor has completely stopped.Switch the auxiliary winding connections and reconnect the power without waiting for the motor to stop.None of the above procedures will reverse the rotation direction.

10.What happens to a reluctance motor when the load increases beyond its capacity to maintain synchronous speed?

It loses stabilityIt consumes too much armature current and risks damageIt loses synchronism and stops rotatingIt operates like an induction motor

11.Which type of bearings are commonly used in most fractional horsepower motors?

Bearings that are hard and annealedRoller or ball bearingsBearings that are soft and porousSleeve or plain bearings

12.What is the primary reason for brush sparking in a universal motor?

13.Which of the following statements about a reluctance-start motor is false?

It operates exactly like a reluctance motor.It fundamentally functions as an induction motor rather than a synchronous motor.Its core operating principle resembles that of a shaded pole motor.The air gap between the rotor and the salient poles is uneven.

14.What happens if the starting winding of a single-phase induction motor remains connected in the circuit?

The motor operates at a higher speedIt causes sparking when under light loadIt pulls too much current and overheatsThe motor runs at a reduced speed

15.What is the likely consequence if the centrifugal switch in a dual-capacitor motor fails to open as intended?

The motor will fail to reach its rated speed.The motor will be unable to handle the mechanical load.The motor will experience an abnormally high current draw.The electrolytic capacitor is likely to be damaged.The motor will operate at reduced efficiency.

Single Phase Induction Motors MCQs

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