Basic Motor Concepts

What is the function of the stator in an electric motor?

• Rotate the shaft

• Generate magnetic fields

• Store energy

• Control voltage

What rotates in a basic electric motor?

• Stator

• Frame

• Rotor

• Bearing

The rotor in a motor is moved by:

• Friction

• Centrifugal force

• Magnetic attraction and repulsion

• Hydraulic pressure

A two-pole stator motor completes one rotation for how many cycles of AC?

• One full cycle

• One-half cycle

• Two cycles

• Each half cycle

Why won’t a motor start with equal and opposite attraction from the stator?

• The rotor is locked

• No phase shift is present

• Voltage is too low

• Rotor is misaligned

Shaded-pole motors have:

• High torque

• Low cost

• High efficiency

• Start capacitors

What provides phase shift in a shaded-pole motor?

• Start winding

• Start capacitor

Direction of rotation in shaded-pole motors is toward:

• The unshaded side

• The shaded pole

• The rotor axis

• The stator windings

To reverse a shaded-pole motor, you must:

• Change the capacitor

• Reverse the power supply

• Turn the stator and fan blade

• Add a phase winding

Shaded-pole motors are often:

• Water-cooled

• Impedance protected

• Explosion proof

• Three-phase