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Worksheets03. ACR-105 UNIT 13 PRACTICE TEST
Total questions: 10
Worksheet time: 5mins
Electrical, mechanical, electromechanical, digital, and pneumatic are all types of ________.
fuses
controls
circuit boards
motors
_________ are typically normally closed devices that open their contacts only when the device senses system conditions that are outside the designed operating range.
Bimetal devices
Pneumatic controls
Rod and tube controls
Safety devices
The main purpose of the HVAC/R industry is to control space or product conditions by controlling _________.
temperature, humidity, air quality, and air cleanliness
air quality, air infiltration, and air distribution
power consumption, temperature, and fuel efficiency
temperature and power consumption
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 bimetal strip is lengthened
the voltage to the device is modulated
the device should be mounted perfectly level
the bimetal strip is shortened
A column of temperature-sensitive fluid rising and falling within a hollow stem in response to a sensed temperature or level of heat intensity best describes the function of a ________.
thermometer
pneumatic control
snap-disc
thermistor
A ________ is a thin, flexible, movable membrane that is used to convert pressure changes to movement or motion in a control.
diaphragm
bimetal coil
snap-disc
control bulb
An accordion-like device that expands and contracts when internal pressure (usually vapor) changes is a ________.
thermocouple
bellows
Bourdon tube
diaphragm
A _______ varies its resistance to current flow based on its temperature.
thermometer
thermopile
thermistor
thermocouple
If a thermistor increases its resistance as the temperature increases, it has a negative temperature coefficient (NTC).
True
False
