FREE AND STUDY GAMES ABOUT MOTORS EXAM

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FREE AND STUDY GAMES ABOUT MOTORS EXAM

QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -23 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: true/false In the 3-lights-out method of manual alternator synchronization, the phase connection is incorrect if the lights do not all turn on and off at the same time.

Answer:

true Question 2: Portable generators are rated by their maximum power output, surge power output, and ? output(s).

Answer:

voltage

Question 3: The speed of a 6-pole AC generator operating on 60 hertz is ? .

Answer:

1,200 rpm s=(120xf)/poles

Question 4: true/false

With automatic synchronization, a controller monitors the frequency, phase angle, current of the incoming source, and current of the busbar.

Answer:

false

a controller monitors the frequency, phase angle, and Voltage of the incoming source and the busbar.Question 5: true/false Alternators are rated according to the maximum load they can withstand.

Answer:

false alternators are rated according to the load they can maintain on a continuous basis.Question 6: At position ? of the sine wave, the rotor voltage has changed to its maximum negative value.

Answer:

D Question 7: A ? can be used to match two alternators, or to help match the frequency and phase of an alternator to a busbar.

Answer:

synchroscope Question 8: If there is a(n) ? mismatch, a slowly turning alternator is a load to other alternators.

Answer:

frequency Question 9: A portable generator is being specified for a job site where a one-horsepower compressor and a 200-ampere electric welder are to be operated. The recommended minimum-size generator (based on 25% additional power) for operating power should be ? .

Answer:

15,000 W

Question 10: true/false

In manual synchronization, it is easier for the alternator rotor to slow down than to speed up.

Answer:

true Question 11: Though not the common practice today, 3-phase AC power can be generated by rotating three coils through the ? .

Answer:

magnetic field

Question 12: true/false Large alternators are often powered by steam turbines, which use natural gas, nuclear energy, coal, or oil as fuel to generate steam.

Answer:

true

Question 13: ? is often used to cool small AC alternators.

Answer:

Air

Question 14: what factor will not control the output voltage of an alternator?

Answer:

The number of poles

Question 15: An AC alternator is a synchronous machine that produces ? .

Answer:

alternating current (AC) Question 16: A(n) ? is an alternator in which a fixed magnetic field is created in the stator, with the rotor turning within the stator, and AC power is supplied through the rotor slip rings and brushes.

Answer:

revolving-rotor alternator Question 17: It is common for utilities that generate high-voltage power to use ? .

Answer:

revolving-field alternators Question 18: The ? output from an alternator or generator must be between +5%/?10% of the requirements for the load(s).

Answer:

voltage Question 19: What is the first step in determining the correct size of a generator for an application?

Answer:

List the electrical loads that must be operated by the generator.

Question 20: A rectifier assembly mounted on the main rotor shaft along with the exciter generator is referred to as a(n) ? .

Answer:

brushless exciter Question 21: Alternators are rated in kilowatts at a standard power factor of ? .

Answer:

80% Question 22: AC power is ? in the United States and Canada, and ? in Europe and other parts of the world.

Answer:

60 Hz / 50 Hz Question 23: A(n) ? is the power source used to turn the rotor that creates the relative motion between the coil and the magnetic field.

Answer:

prime mover