Quiz sheet for machines

A dc series motor should never be run unloaded, as this will cause the motor to:

A) over speed

B) slow down

C) overload

D) overheat

ANSWER: A

A self-excited shunt generator relies on ______ ______ for its initial magnetic flux.

A) Residual magnetism

B) Separate excitation

C) Field flashing

D) Good luck

ANSWER: A

If a generator is connected for a shunt configuration, the field connections would be a ______ resistance field connected in ______ with the armature.

A) High, parallel

B) High, series

C) Low, series

D) Low, parallel

ANSWER: A

If a self excited shunt generator is driven in the reverse direction and all other factors remain the same, then:

A) it will not "build-up" to rated voltage

B) it will "build-up" to rated voltage but terminal polarity will be reversed

C) it will "build-up" to rated voltage and terminal polarity will be unaltered

D) it will overload the prime mover

ANSWER: A

In a dc shunt motor, the __________ and __________ are constant.

A) field current, field flux

B) field flux, armature current

C) field flux, armature flux

D) field current, armature flux

ANSWER: A

The DC motor with the highest starting torque is 

A) Series

B) compound

C) shunt

D) permanent magnet

ANSWER: A

The emf generated in the armature of a DC motor is proportional to 

A) the speed

B) the armature current

C) load

D) good wishes

ANSWER: A

To determine forces acting on a current carrying conductor within a magnetic field, you would use 

A) Flemings left hand rule 

B) Flemings right hand conductor rule

C) Flemings right hand solenoid rule

D) Flemings right hand rule for motors

ANSWER: A

When a motor is driving a load, a ______ is generated in the armature conductors which ______ the applied motor voltage.

A) back emf, opposes

B) Mutual emf, increases

C) Mutual emf, opposes

D) back emf, increases

ANSWER: A

Whilst driving a load, a ______ is generated in the armature conductors which ______ the applied motor voltage.

A) back emf, opposes

B) back emf, increases

C) Mutual emf, opposes

D) Mutual emf, increases

ANSWER: A

Last modified: Tuesday, 1 June 2021, 9:21 AM