1. Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in armature reaction are compensated for by the

a] governor and speed drop setting
b] voltage coil
c] balance coil
d] phase balance relay

2. Voltage generated by most AC generators is fed from the machine to the bus by means of

a] brushes on a commutator
b] brushes on slip rings
c] slip rings on a commutator
d] direct connection from the stator

3.In an AC generator, direct current from a separate source is passed through the windings of the rotor

a] by means of slip rings and brushes
b] by means of a commutator 
c] by means of rotating bar magnet
d] to minimize the danger of arc over

4. A constant output voltage from an AC generator is maintained by

a] prime mover governor
b] exciter generator
c] voltage regulator
d] reverse power relay

5. The output voltage of a three-phase alternator is regulated by the

a] AC voltage to armature
b] AC voltage to field
c] DC voltage to the armature
d] DC voltage to the field

6. You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry,
clean winding will

a] continue to rise as the test potential is maintained, becoming fairly steady as the leakage current stabilizes
b] remain constant as the temperature of the windings increases
c] continue to drop as the potential is maintained, becoming fairly steady after 5 to 7 minutes
d] stabilize after approximately 2 to 4 minutes of fluctuation

7. Kilowatt load is divided between two AC generators operating in parallel by

a] adjusting the governor controls
b] varying the excitation voltage
c] increasing both prime mover speeds simultaneously
d] decreasing both prime mover speeds simultaniously

8. The frequency of an alternator at a given RPM is determined by

a] number of turns of wire in the armature coil 
b] number of magnetic poles 
c] strength of the magnets used
d] output voltage

9. Which of the following will happen to the alternator frequency if the load is removed from a turbo generator, whose governor has a 3% speed droop? 

a] it will remain unchanged
b] it will decrease by approximately 3%
c] it will increase
d] it may increase or decrease

10. As load is added to an AC generator provided with constant field excitation, the prime mover slows down with the effect of

a] lowering frequency and lowering generated voltage
b] increasing frequency and increasing generated voltage
c] increasing frequency and lowering generated voltage
d] lowering frequency and increasing generated voltage

11. Which is a function of the voltage regulators used with AC generators?

a] To cut out generators when they are no longer required.
b] To cut in additional generators automatically as required.
c] To divide the KW load equally between generators operating in parallel.
d] To divide reactive current between generators operating in parallel.

12. The governor control switch of an alternator is moved to the "raise" position. This action will

a] raise the no-load speed setting of the governor
b] raise the percentage of speed droop
c] lower the no-load speed setting of the governor
d] lower the percentage of speed droop

13. The main purpose of an electric space heater installed in a large AC generator is to

a] prevent the windings from becoming brittle
b] prevent moisture from condensing in the windings during shutdown
c] prevent acidic pitting of the slip rings
d] keep the lube oil warm for quick starting

14. Prior to starting an AC generator prime mover, the voltage regulator cutout switch should be placed in the

a] manual position
b] bus neutral position 
c] raise voltage position 
d] transfer position

15. Excessive humming of AC contactors may be caused by

a] burnt arc shields 
b] shorted armature coils 
c] a broken shading coil
d] high voltage

16. The cycles per second developed by the alternator aboard your vessel is determined by

a] the speed of the engine driving the alternator
b] the resistance applied to field rheostat
c] the synchronous speed of induction
d] the adjustments made to the voltage regulator

17. AC and DC generators are similar in that they

a] both generate alternating voltages 
b] both rectify the voltage before delivery 
c] are constructed at the same physical size for the same kilowatt rating
d] both supply three-phase power

18. Which of the following devices are protected from being motorized by a reverse-power relay?

a] alternator
b] wave guides
c] exciters
d] Amplidynes

19. A bus disconnect link is used to isolate

a] one bus bar from another
b] the generator circuit breaker from the bus
c] different phases from the equalizer connection
d] positive and negative buses from nuetral

20. If the excitation is increased to one of two alternators operating in parallel, the

a] power factor will change in the lagging direction
b] power factor will change in the leading direction
c] kilowatt load will be greatly increased
d] ampere load will be greatly decreased

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