Unit 5 Review Part-1

1. The armature direction of rotation depend on______________

• Magnetic field polarity & direction of current in the armature conductor

• Armature motion and magnetic polarity

• Direction of current and motor type

• Direction of current and commutator connection

Which direction does the current-carrying conductor in a magnetic field will move around a magnetic field on a Dc motor?

• Left angles to direction of field

• Downward to direction of field

• Right angles to direction of the field

• Right angles to direction of the auxiliary winding

In Fleming’s right-hand rule, the thumb represents

• Direction of magnetic field

• Direction of current flow

• Direction of conductor

• Direction of voltage

If the polarity of the supply current for an operating DC series motor is reversed,

• the armature current reversed

• the armature current not reversed

• Run in the opposite direction

• Run in both directions

What happens if the polarity of the supply current in a DC series motor is reversed

• magnetic field polarity remains the same and current direction will revers

• magnetic field polarity will reverse and armature current direction is the same

• both magnetic field polarity and armature current direction will reverse

• both magnetic field polarity and armature current direction will remain the same

If the polarity of the supply current for an operating DC series motor is reversed, the motor will

• Not run

• Run in the same direction

• Run in the opposite direction

• Run in both directions

When the commutator changes direction of current flow in the armature The motor will

• turn in the opposite direction

• continue to turn in the same direction

• stop turning

• Nothing will happen

What happens to motor if you change the direction of current in the armature or field (but not both), of the DC motor?

a.

• Will not run

• Will run in the same direction

• Will run in the opposite direction

• Will burn

Which converts a single-phase power supply into two separate electrical phases at 90 electrical degrees apart?

• Bearing

• Capacitor

• Running winding

• Centrifugal switch

To start the single-phase motor rotation

• The start winding energized the run winding de-energized

• The start winding is energized

• The run winding is energized

• Both start and run winding is energized