Answer ALL questions. Look for any feedback given if you get an answer incorrect. Keep choosing an answer until you get it correct. CORRECT or INCORRECT answers are indicated at the TOP of the page. A score is given at the TOP of the page when the exercise has been completed.
How is a large synchronous motor started ?
manual rotation starting
self starting
DOL starting
Rotor resistance starting
What principle is being shown here?
3 phase synchronous motor
single phase synchronous motor
3 phase squirrel cage induction motor
4 pole-pair motor arrangement
If the rotor of an AC motor is fed a constant current via slip-rings, so making the rotor act as a permanent magnet, what type of motor arrangement is produced ?
3-phase synchronous motor
AC stepper motor
single-phase induction motor
Linear motor
What method is used throughout the automation industry to control the speed of synchronous motors ?
variable frequency drive
rotor resistance starter
star/delta starter
DOL starter
What can occur if an excessive load is placed on a synchronous motor ?
nothing - a synchronous motor keeps constant speed
it will stall
the current drawn from the mains supply will trip out the MCB's or rupture the fuses in the fuseboard
speed will drop slightly
Onto what part of a dc motor do the 'carbon brushes' connect directly ?
field winding
bus-bars
commutator
slip-rings
What type of motor design is shown here?
DC shunt
DC series
AC synchronous
AC induction
What type of motor design is shown here?
DC shunt
DC compound
universal
AC induction
What is the advantage of the type of motor design shown here when under load?
high torque, high current
high torque, low speed
low torque, high speed
low torque, low current
What type of motor must not be run with no load applied?
DC series wound
DC shunt wound
AC induction motor
synchronous motor
What is the advantage of the type of motor design shown here?
high torque, high current
high torque, low speed
low torque, high speed
low torque, low current
What type of starter/speed-controller is shown here?
DOL
Star/Delta
variable frequency
rotor-resistance
What type of motor arrangement is shown here?
compound
series wound
shunt wound
synchronous
In order to calculate synchronous speed of a polyphase motor, one must know the frequency of the supply, number of pole-pairs and one other factor. What is this factor?