# Synchronization of Single & Three Phase of Alternators - MCQs with answers

## Synchronization of Single & Three Phase of Alternators - MCQs with answers

Q1. In lamps dark method for synchronization of single phase alternator, if the frequency of the two alternators is exactly same as well as their voltages are in exact phase opposition then the resultant voltage will be

a. Sum of the voltages of two alternators
b. Equal to the voltage of alternators
c. Zero
d. None of these

Q2. If the frequencies of the two alternators in lamp dark method for synchronization of alternators are unequal, then the two lamps will

a. Glow together
b. Become alternately bright and dark
c. Not glow at all
d. None of the above

ANSWER: b. Become alternately bright and dark

Q3. For synchronization of single phase alternators which method gives the more accurate result?

a. Lamps dark method
b. Lamps bright method
c. Both (a) and (b)
d. None of these

Q4. While synchronization of three phase alternators by lamps bright and dark method, if the lamps pair becoming dark and bright simultaneously, it indicates

a. Incorrect phase sequence
b. That the frequencies of alternators are different
c. That voltage of the alternators are not in phase opposition
d. All of the above

Q5. For synchronization of alternators, the most suitable method is

a. Lamps method
b. Voltmeter
c. Synchroscope
d. None of the above

Q6. What does the pointer of synchroscope indicates when it is rotating in anticlockwise direction and when it is rotating in clockwise direction?

a. Incoming machine is running slow, incoming machine is running faster
b. Incoming machine is running faster, incoming machine is running slow
c. Pointer rotates only in clockwise direction
d. All of the above

ANSWER: a. Incoming machine is running slow, incoming machine is running faster