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The mechanical device which converts mechanical input into alternating current out is a(n)
Alternator
The direct current that is an input to the alternator's rotor is the _ current
Excitation
An alternator containing eight poles per phase is turning at 1500 RPM. What is the output frequency?
100 Hz
Connection to the armature of an alternator is normally done by using
Sliprings
The higher power output alternators use a
Revolving field
In order to increase the efficiency of the cooling, some alternators operate in an atmosphere of
Hydrogen
In an alternator, when the rotor DC excitation current is removed there is a possibility of damaging high voltages being developed. In order to limit voltage and thereby prevent damage, a _ or a diode can be included in the circuit
Field discharge resistor
A three phase alternator containing eight poles is turning at 900 RPM. What is the output frequency?
60 Hz
The revolving armature type of alternator is capable of _ power output and is, therefore, _ often used than the revolving field type
In order to increase the efficiency of the cooling, some alternators operate in an atmosphere of
Hydrogen
Because some of the input energy to the alternator ends up being converted into heat, often cooling is required. The main types of cooling media are
Air and Hydrogen
In a three phase alternator, the direction of magnetic field rotation is also called
Phase rotation
An alternator containing eight poles per phase is turning at 1000 RPM. What is the output frequency?
66.6 Hz
Connection to the armature of an alternator is normally done by using
Wave-wound armatures
The rotating part of an alternator is called the
Rotor
Two alternators are being connected to supply power to a load. After the connection is made, in order to make the added alternator share the load, the input torque to the alternator being added must be
Increased
The output frequency of an alternator is controlled by the
1200 Hz
The entire assembly of iron core, commutator, and windings is called the
Armature
The non-rotating part of an alternator is called
Stator
At a pressure of one atmosphere hydrogen has a specific heat of approximately
3.42
In order to parallel two alternators, they must be producing the same voltage, have the same phase rotation, and be in phase. To check the phase angle difference, you can use a test set called a(n)
Calculate frequency if a motor with 6 poles and needs to go 2300 RPM
115 Hz
The three basic types of armature windings are
Lap, wave, and frogleg
An alternator that has a separate small alternator mounted on the shaft of its rotor is equipped with a(n)
Brush less exciter