## 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

D) overheat

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

A) Residual magnetism

B) Separate excitation

C) Field flashing

D) Good luck

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

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

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

The DC motor with the highest starting torque is

A) Series

B) compound

C) shunt

D) permanent magnet

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

A) the speed

B) the armature current

D) good wishes

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

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

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