1. A distinguishing feature of the synchronous motor is that it runs without slip at a speed determined by the frequency
of the connected power source and the number of poles it contains.
a. True
b. False
2. The rotor is excited by a source of direct current so that it produces simultaneous north and south poles.
a. True
b. False
3. Synchronous motors are constructed almost exactly like alternators.
a. True
b. False
4. AC loads generally have a lagging power factor.
a. True
b. False
5. A disadvantage of the synchronous motor equipped with a brushless exciter is that brush sparking is eliminated.
a. True
b. False
Name: Class: Date:
Unit 39 Synchronous Motor Operation
6. The synchronous motor sets up a rotating field through ____ coils energized by alternating current.
a. DC b. stator
c. available d. contactor
7. The rotor must have the same number of poles as the ____.
a. cage b. main
c. stator d. auxiliary
8. A synchronous motor converts AC electrical energy into ____ power.
a. thermal b. hydraulic
c. pneumatic d. mechanical
9. A method for applying excitation current to the rotor is with a ____ exciter.
a. rectifier b. brushless
c. complementary d. supplementary
10. An advantage of the synchronous motor equipped with a brushless exciter is that ____.
a. field control and excitation are provided by a static system
b. brush sparking is produced
c. field excitation is manually removed whenever the motor is out of step
d. manual resynchronization can be achieved whenever it is practical
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Name: Class: Date:
Unit 39 Synchronous Motor Operation