( )provide visual indication of the status for many motor-controlled processes permitting personnel at remote locations to observe the current state of the operation.
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The difference between a push button and selector switch is( ).
A( )is one that is controlledautomatically by factors such as pressure, position, andtemperature.
( )are devices that are used to detect, and often to measure, the magnitude of something.
Photoelectric sensors are composed of two basic components: a transmitter (light source) and a ( ).