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Solenoids, Relays, And Motors

Posted by

notesuser

On April 23, 2020

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Questions 1–25:

Select the best answer to each question.

1. An electromagnet becomes stronger when the

A. current through the magnetizing coil is increased.

B. core of the magnet is removed.

C. size of wire in the coil is increased.

D. number of turns in the coil is reduced.

2. The purpose of the shading coil in some appliance motors is to

A. increase the current flow through the rotor.

B. cause imbalance in the magnetic field.

C. place more weight on one pole.

D. strengthen the iron form of the motor.

3. The rotor in a shaded-pole motor consists of

A. coils energized by alternating current. C. a permanent magnet.

B. a short-circuited loop of copper wire. D. an iron cylinder.

4. Why does a shaded-pole motor run at a constant speed?

A. The lines of force do not change direction.

B. The current through the rotor circuit is constant.

C. The inertia of the load is at a minimum.

D. The