SINGLE PHASE INDUCTION MOTOR

What creates a rotating magnetic field in an induction motor?

• The angular speed of the motor

• Three phase current flowing in the rotor

• Three phase current flowing in the stator

• A single phase current flowing in both the rotor and the stator

A single phase induction motor employs ________rotor

• squirrel cage

• wound

• either squirrel cage or wound

• none

The purpose of starting winding in a single phase induction motor is to_____

• reduce losses

• limit temperature rise of the machine

• produce rotating flux in conjunction with main winding

• none

The direction of rotation of a single phase motor may be achieved by

• changing over the supply phase and neutral

• reversing the connections to both start and run windings

• reversing the connections to either start or run windings

• reversing the connections to the centrifugal switch.

What component is required to control the starting capacitor in a single phase induction motor?

• shunt coil

• thermal trip

• discharge resistor

• centrifugal switch

In a split-phase motor, the running winding should have

• High resistance and low inductance

• High resistance and High inductance

• Low resistance and high inductance

• Low resistance and low inductance

If the capacitor of a single-phase motor is short-circuited

• The motor will not start

• The motor will run in the same direction at a reduced speed

• The motor will run in the reverse direction

• None of the above

In a split-phase motor

• Both starting and running windings are connected through a centrifugal switch

• Centrifugal switch is used to control supply voltage

• The running winding is connected through a centrifugal switch

• The starting winding is connected through a centrifugal switch

The torque developed by a single-phase motor at starting is

• less than the rated torque

• More than the rated torque

• zero

• None of the above

A centrifugal switch is used to disconnect ‘starting winding when motor has

• Picked up 10% speed

• Picked up 20% speed

• Picked up 5 – 10% speed

• Picked up 50 – 70% speed