Unit 13 Review Questions

A thin, flexible metal disc with a large surface area is a ​ .​ (a)   ​

• Diaphragm
• Bellows​
• Expander

What is the device that consists of two unlike metal strips that are attached and have a different rate of expansion and contraction?

• Bimetal

• Diaphragm

• Thermocouple

• Thermistor

An accordion-type device with a large internal volume that has a lot of travel is referred to as a         .

Which of the following is a device consisting of two unlike metals fastened at one end that, when heated on the fastened end, produces a DC current?

• Thermocouple

• Thermistor

• Diaphragm

• Bimetal

Electrical, mechanical, electromechanical, digital, and pneumatic are all types of ________.

• Controls

• Circuit Boards

• Motors

• Fuses

_________ are typically normally closed devices that open their contacts only when the device senses system conditions that are outside the designed operating range.

When a bimetal device is heated, the steel expands faster than the brass, which causes the device to warp.

• True

• False

To make bimetal devices practical over a wider temperature range, ________.

• the voltage to the device is modulated

• the device should be mounted perfectly level

• the bimetal strip is lengthened

• the bimetal strip is shortened

If a thermistor increases its resistance as the temperature increases, it has a negative temperature coefficient (NTC).

• True

• False