Weekly Assessment on Motor Skills

What is the most common cause of a single-phase motor not starting but making a humming sound?

• Faulty windings

• Faulty capacitor

• Overvoltage

• Loose connections

If a single-phase motor overheats, what should you check first?

• Motor bearings

• Airflow and ventilation

• Rotor alignment

• Start switch

What tool would you use to check for continuity in the windings of a motor?

• Capacitance meter

• Megger (insulation tester)

• Multimeter

• Oscilloscope

Which of the following can cause a motor to run at a lower speed than normal?

• Voltage drop

• Worn bearings

• Incorrect capacitor

• All of the above

What does a thermal overload in a motor protect against?

• High voltage

• Excessive temperature

• Electrical noise

• Low torque

If a single-phase motor stops abruptly after running for some time, what could be the cause?

• Loose wiring

• Thermal overload protection triggered

• Capacitor failure

• Bearing wear

A motor running but producing an unusual grinding noise could be due to:

• Low voltage

• Bearing failure

• Open windings

• Shorted capacitor

How would you diagnose a fault if the motor windings have a short circuit?

• Using a multimeter to check continuity

• Checking voltage at terminals

• Using a megger to test insulation resistance

• Testing with a capacitance meter

What is a possible reason for a motor failing to start even when the power supply is correct?

• Open start winding

• Good capacitor

• Balanced voltage

• Rotor free movement

If a motor experiences low voltage supply, what could be a consequence?

• The motor runs at a higher speed

• The motor overheats

• The motor runs more efficiently

• The motor runs smoothly