____________________ are designed to produce an output voltage that is proportional to the strength of a magnetic field.

Circuits that permit the automatic starting of motors in sequence are rare.

Figure 17-11 The accompanying figure is showing a(n) ____________________.

Float switches are used to control the action of a(n) ____________________ in accordance with the level of a liquid in a tank or sump.

Air flow switches are often called ____________________.

Instantaneous contacts change their positions immediately when the coil is energized and change back to their normal positions immediately when the coil is de-energized.

Hall originally used a piece of pure gold to produce the Hall effect, but today a piece of ____________________ material is used instead.

Figure 19-03 The accompanying figure shows a detector that uses a tank circuit tuned to the frequency of the oscillator. This type of sensor is a(n) ____________________.

Figure 15-6 In the accompanying diagram, a(n) ____________________ controls the operation of the compressor.

____________________ is generally used to help the electrician interpret the meaning of certain components and find contacts that are controlled by coils.