Alternators must run at constant speed in order to maintain
a) current
b) power
c) voltage
d) resistance
e) frequency
Answer: E
Learn More :
Power Engineering Chapter 81
- Apparent power is the power
- To transfer the power to or from the rotor of alternators or some AC motors
- Brush gear for DC machines have brushes made from carbon because they:
- Synchronous motors have construction that is identical to
- The yoke that supports the main components of the DC machine is frequently made of
- Shunt wound DC motors are common where speed must remain constant regardless of load such as on
- ______ are used on motors and generators to set up a magnetic field.
- A 6 pole alternator producing 60 Hz power must turn at
- The stator of an alternator is built of ______ mounted in a frame.
- The rotating field of an alternator is obtained by exciting the windings on the rotor with
- A compound wound DC generator may have three characteristics which are a: 1. decreasing output voltage versus load 2. no amperage requirement 3. constant output voltage 4. supplementary AC requirement 5. rising output voltage versus load
- The field rheostat changes the ______ in a DC generator.
- The commutator of a DC machine is made of copper bars mounted in
- The field rheostat in a DC generator is used to adjust the ______ of the motor.
- When synchronizing an alternator; voltage, phase and frequency must all be the same as well as
- A rheostat or "voltage regulator" of a DC shunt wound generator is used to
- A common use for a DC generator is
- The space around a magnet, through which the imaginary magnetic lines of force are considered to travel, is known as the
- The connection provided on DC motors to supply the armature with power
- The field strength of an alternator may be changed by varying the amplitude of the DC power, supplied to the rotating field by:
- Three factors which control the electromotive force developed by a DC generator are the:
- The three main types of DC generators are the: 1. compound wound 2. parallel wound 3. series wound 4. reverse wound 5. shunt wound
- The magnetic field in a DC machine may be supplied by permanent magnets in small units. Large DC machines use field poles that are essentially
- The armature core of a DC machine is built up of laminations of
- In order to produce the strength of magnetic flux required in larger DC machines