ATT TEST 3 QUESTIONS AND ANSWERS 2025
This schematic represents what type of rotating machine?
- .....ANSWER ...✔✔ Separately excited DC
generator
How is a pulsating DC output eliminated in DC
generators? - .....ANSWER ...✔✔ Using a multiple-
loop armature
What part of a motor allows reversing the magnetic
poles in the rotor? - .....ANSWER ...✔✔ Commutator
and brushes
What principle of magnetism allows a generator to
power its own stator windings and still generate an
output voltage? - .....ANSWER ...✔✔ Retentivity
In a generator, when the armature rotation is parallel to
the stator magnetic field, what is the output voltage? -
.....ANSWER ...✔✔ zero
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In the motor's voltage source circuit, what is the purpose
of IC1? - .....ANSWER ...✔✔ Voltage regulator
In the motor's voltage source circuit, what is the purpose
of R8? - .....ANSWER ...✔✔ Manual speed control
In the automatic speed control circuit, what happens to
the frequency output of ISO1 if the load on M2
increases? - .....ANSWER ...✔✔ decrease
In the automatic speed control circuit, what happens to
the output of U2 if the load on M2 decreases? -
.....ANSWER ...✔✔ increase
During troubleshooting of a motor-generator set, if the
set is not rotating, what is the probable faulted area? -
.....ANSWER ...✔✔ Motor and motor circuits
What principle of magnetism allows the use of
electromagnet stators? - .....ANSWER ...✔✔ Passing a
current through a conductor produces a magnet
This schematic represents what type of rotating machine?
- .....ANSWER ...✔✔ Series DC motor
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What principle of magnetism do motors operate on? -
.....ANSWER ...✔✔ Attraction and repulsion
In the motor's voltage source circuit, what is the purpose
of U1? - .....ANSWER ...✔✔ Difference amplifier
In a motor, it is important to know that the starting
current _______ - .....ANSWER ...✔✔ is higher than
the running current.
What principle of magnetism do generators operate on?
- .....ANSWER ...✔✔ Passing a conductor through a
magnetic field produces voltage
How do you troubleshoot an automatic speed control
circuit in a motor-generator set? - .....ANSWER ...✔✔
Signal tracing circuits
What is the primary difference between a DC motor
and DC generator? - .....ANSWER ...✔✔ The power
source to the rotor is replaced in a generator with a
load.
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In U1, if the non-inverting input voltage remains constant
and the inverting input voltage increases, what happens
to the output voltage? - .....ANSWER ...✔✔ Decreases
What principle of magnetism allows the use of
electromagnet stators? - .....ANSWER ...✔✔ Passing a
current through a conductor produces a magnet
What level of voltage is produced in an AC generator
when the armature movement is parallel to the stator
field? - .....ANSWER ...✔✔ None
In the revolving-field generator, there are no sliding
contacts in the _______ - .....ANSWER ...✔✔ AC
output circuit.
In a Delta connected alternator, the line voltage equals
the _______ - .....ANSWER ...✔✔ phase voltage
In three-phase alternators, the windings are connected in
either a Wye or _______ configuration. - .....ANSWER
...✔✔ Delta