Motors

Which type of machine would require greater maintenance?

• Single-phase induction

• DC series

• Asynchronous

• Synchronous

Which type of single-phase induction motor is used where greater starting torque is required?

• Capacitor start

• Shaded pole

• Split-phase

• DC shunt

Which type of single-phase induction motor uses copper to create a pulse magnetic field?

• Capacitor start

• Shaded pole

• Split-phase

• Squirrel cage

Which DC motor is designed to maintain a constant speed irrespective of the load imposed on it?

• DC universal

• DC series

• DC shunt

• DC compound

Which type of motor is dangerous to start up without load?

• Capacitor start

• DC series

• DC shunt

• Split-phase

Where is the capacitor connected within a split-phase capacitor start motor?

• Across the cage

• In series with the run winding

• In series with the start winding

• In parallel with the run winding

Which type of motor is typically used in a lift where both high initial torque and constant speed is required?

• DC universal

• DC series

• DC shunt

• DC compound

Select two uses of synchronous motors.

• They are used where high torque is required for heavy loads

• They are used where high speed is required for heavy loads

• They are used where correction for power factor is required

• They are used where constant and precise speed is required

What is the synchronous speed of an 8-pole machine connected to a 50Hz supply?

• 6.25rpm

• 6.25rps

• 12.5rpm

• 12.5rps

Which is a single-phase induction motor?

• DC shunt

• Shaded pole

• Squirell cage

• Wound roto