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.

Figure 10-5 A single pole, single throw toggle switch provides jog or run control in the accompanying figure. If the switch is in the OFF position, the holding contacts can seal the circuit when the START button is released.

A control relay is used to provide jogging in one direction only.

What is a hazard of push buttons?

The air flow switch is constructed from a(n) ____________________ micro switch.

Pneumatic timers are affected by variations in ambient temperature or atmospheric pressure.

The abbreviations TO and ____________________ are used with some control schematics to indicate a time-operated contact.