The mighty motor video questions

Name three materials that the frame can be made from

• Sheet steel

• Cast iron

• Cast aluminium

• Copper

What material are the stator and rotor laminations made from?

• Polycor steel

• Aluminium

• Copper

• Ferrite

Why are laminations used in the stator and rotor?

• To increase hysteresis

• To reduce hysteresis

• To reduce eddy currents

• To increase eddy currents

What is meant by the ‘IP’ rating?

• Increased protection

• Ingress protection

• Item portabilty

• Internal protection

Why are the stator and rotor laminations heated in an inert atmosphere and then exposed to air?

• To remove surface oxidation

• To harden the surfaces

• To reduce surface oxidation

• To oxidise their surfaces, and to anneal the metal

What are the stator coils made from?

• Aluminium

• Bare copper wire

• Enamelled copper wire

• Steel wire

How is overheating of the stator detected?

• By embedding thermistors in the windings

• By embedding resistors in the windings

• By embedding transistors in the windings

• By embedding flux capacitors in the windings

What electrical tests are applied to the stator? 

• Resistivity

• Phase rotation

• Continuity

• Insulation resistance

What is the cage constructed of? 

• Aluminium

• Steel

• Copper

• Iron

How is vibration of the rotor minimised? 

• By balancing the stator

• By balancing the rotor

• Reducing the length of the rotor

• Reducing the diameter of the rotor