Exam 32: Three-Phase Alternators

The rotating part of a revolving-armature-type alternator is called the _____.

In order to increase the efficiency of the cooling, some alternators operate in a(n) _____ atmosphere.

Using a(n) _____ is one method of preventing induced voltage from becoming excessive.

By increasing or decreasing the strength of the magnetic field of the rotor, the _______________ of an alternator is controlled .

_______________ alternators have a fan attached to one end of the shaft.

If one alternator does not produce sufficient power to supply a load, another alternator can be connected to the circuit. The second alternator is connected in _____.

An alternator containing eight poles per phase is turning at 1500 RPM. What is the output frequency?

What is one factor that controls the output frequency of an alternator?

A three-phase alternator containing six poles is turning at 1000 RPM. What is the output frequency?

The direction of magnetic field rotation is known as _____ rotation.

An alternator that has a separate small alternator mounted on the shaft of its rotor is equipped with a(n) _____.

The non-rotating part of a revolving-field-type alternator is called the _____.

An alternator containing eight poles per phase is turning at 900 RPM. What is the output frequency?

Alternators of small kilovolt-ampere rating are generally _____ -cooled.

The revolving armature type alternator is capable of _____ power output and is, therefore, _____ often used than the revolving field type.

What machines operate on the same principle of electromagnetic induction as DC generators, but they have no commutator?

A(n) _____ is used to measure the difference in voltage and frequency between two alternators.

The direct current that is an input to the alternator's rotor is the _____ current.

Power is carried to the outside circuit of a  revolving armature type alternator  via brushes riding against the _____.

The higher power output alternators use a revolving _____.