Input/Output Devices and Motor Controls Quiz

What are pushbuttons and switches also called?

• Continuous input devices

• Discrete input devices

• Digital input devices

• Analog input devices

What is the characteristic of a normally open pushbutton?

• Remains in that condition until its state is changed

• Can be physically changed to ON or OFF position

• Always closed—until they are forced to open

• Always open—until they are forced to close

What type of switch requires an operator to change its state?

• Limit switch

• Automatic switch

• Manual switch

• Temperature switch

What do proximity sensors detect?

• Liquid level

• Existence of an object

• Pressure

• Temperature

How do inductive sensors detect the presence of nearby metallic objects?

• By measuring changes in magnetic fields

• By detecting changes in liquid level

• By detecting changes in temperature

• By sensing changes in pressure

What is the purpose of ultrasonic sensors?

• To detect temperature

• To detect pressure

• To detect distance to object

• To detect liquid level

What do indicators such as pilot lights, ammeters, and voltmeters help operators do?

• Detect the existence of an object

• Detect the presence of parts

• Visually inspect operation of output devices

• Control power in heavy power cables

What is the function of a relay?

• Protect motor from low voltage and high temperature

• Control velocity, acceleration, and deceleration

• Convert electrical energy into mechanical motion

• Turn a motor on and off

What do contactors control?

• Power in heavy power cables

• Velocity, acceleration, and deceleration

• Switching of large amount of power

• Electrical energy into mechanical motion

What is the characteristic of solid-state relays?

• Use magnetized or demagnetized coil to control switching

• Use capacitive effects to detect object

• Use transistors that can be switched on in the presence of magnetic field

• Use relatively small amount of electrical power to control power