Motors & Generators

Question 1

What occurs if the load is removed from an operating series DC motor?

Answer 1

It will accelerate until it falls apart

Question 2

If a shunt motor running with a load has its shunt field opened, how would this affect the speed of the motor?

Answer 2

It will speed up.

Question 3

The expression “voltage regulation” as it applies to a shunt-wound DC generator operating at a constant frequency refers to:

Answer 3

Voltage fluctuations from load to no-load.

Question 4

A 3 horsepower, 100 V DC motor is 85% efficient when developing its rated output. What is the current?

Answer 4

26.300 amps

Question 5

What is the line current of a 7 horsepower motor operating on 120 volts at full load, a power factor of 0.8, and 95% efficient?

Answer 5

57.2 amps

Question 6

The output of a separately-excited AC generator running at a constant speed can be controlled by:

Answer 6

The amount of field current.