Craig Motors

T or F - a commutator and a collector ring perform the same function in a motor

false

T or F - a commutator turns a rotor ?

false

Define permeability

how well something can become magnetized or conduct magnetic lines of force

The purpose of the iron core rotor is to do what ?

increase permeability

The BLANK shows the direction of magnetic flux when the conductor is grasped in the left hand with the thumb extended in the direction of current flow

left hand flux rule

the reason for heavy initial current inrush is the ?

low resistance of the motor

a BLANK is created in the stator of an induction motor by passing current through the windings

magnetic field

the strength and direction of the field of an electromagnet depends on the strength and direction of the BLANK

magnetizing current

An electric motor is a device for changing electrical enegery into what ?

mechanical power

T or F - all single phase induction motors produce equal amounts of starting torque except for the shade pole motor

true

T or F - magnetic fields never cross; the lines of force either crowd together or cancel eachother out

true

T or F - there is a definite relationship between direction of current flow and direction of flux

true

A motor that does not use a commutator or brushes is called ?

an induction motor

The rotation of a 3-phase motor can be reversed by interchanging what ?

any two leads

an object used to make electrical contact with a collector ring is what ?

brush

what device produces a phase shift in a single phase motor ?

capacitor

it is desireable for an air gap in a magnetic circuit to be as BLANK as possible

close

The ends of the rotor windings are connected to what ?

commutator

Name the 5 types of single phase motors

1. shaed pole 2. split phase 3. permanant split capacitor 4. capacitor start, induction run 5. capacitor start, capacitor run

A 11.19 kw motor can produce how much horsepower ?

15hp

In the united states, the frequency of applied alternating power is regulated by the power companies and is ?

60 Hertz

a 25 horsepower motor produces how many ft/lbs of work ?

825,000

a BLANK is the part of the motor upon which a motors magnetic field acts

rotor

A single phase motor needs a suppplementary device to make it ?

self starting

the natural speed of the rotating magnetic field of the stator is called ?

synchronous speed

the stationary part of a motor is called what ?

the stator

the strength that a motor produces by turning while it is starting or running is called ??

torque