test 2

whats one horse power equal

745

The servomotor which has a fiberglass and copper rotor is the _____ motor

ServoDisc®

How can a Dc motor be made to operate at its base speed

When full voltage is applied to both the armature and shunt field

How can DC motors be made to operate above its base speed

When full voltage is applied to the armature and reduced voltage is applied to the shunt field

Principle of operation of a dc motor

attraction and repulsion of magnetism

What is emf.

back voltage

The motor that does not contain a wound armature, commutator, or brushes is the _____ motor.

brushless

The output voltage of the series generator is set when the load is

connected

Series field windings are connected in series with the armature. They are wound with _____ turns of fairly _____ wire.

few, large

The output voltage of a shunt generator is usually controlled by the amount of

field excitation current

Function of a commutator in a dc motor

mechanical rectifier to change ac produced in the armature to dc

Some DC servomotors have square wave input voltage. To vary the motor speed, the on and off time ratio of the square wave is varied. This is called _____ modulation.

phase

what type of motor should never be operated at no load

series motors must never be operated under a no load motors

In a compound DC motor control circuit, the field loss relay will disconnect the _____ if power is lost to the _____.

shunt field, armature

what type of motor is known as a constant speed motor

shunt motor

What is CEMF.

the induced voltage is opposite to the applied voltage

3 factors that determine the amount of CEMF produced in the armature.

the strength of magnetic field to pole pieces the numbers of turns of wire in the armature the speed of the armature

what two factors determine the amount of torque developed by a dc motor

the strength of the magnetic field of the pole pieces the strength of the magnetic field of the armature

Counter-electromotive force (CEMF) and back-EMF are names for the voltage induced into the armature of a DC motor.

true

what is a motor

turns electrical energy into mechanical energy