Ref. and Air Cond. Tech Unit 1 Flashcards
Temperature can be through of as the level of ____ _________
heat intensity
Temperature is defined as
heat content
The standard conditions for water to boil at 212 degrees Fahrenheit are
an atmospheric pressure of 14.96psia, or 29.92 in. HG
Fahrenheit, Celsius, Ranking, and Kelvin are
temperature scales
Under standard conditions, water freezes at ______
0 degrees celsius
Molecular motion stops at
-460 degrees fahrenheit
One British thermal unit will raise the temperature of 1 pound of water ____________
1 degree fahrenheit
In which direction does heat flow?
from a warmer substance to a cold substance
Heat transfer from molecule to molecule is known as ________
conduction
An increase in sensible heat causes a _______ thermometer reading
higher
Latent heat causes a _______ of state
change
Heat that is transferred by moving in a medium such as air or water is known as _____
convection
Heat that is transferred through space without heating the space and that heats the first object that it strikes is known as
Radiation
Specific heat is the amount of heat necessary to raise the temperature of 1lb of which substance 1 degree fahrenheit
water
Atmospheric pressure at sea level under standard conditions is ____ inches of Mercury (Hg) or _____ pounds per square inch absolute (psia)
29.92 inches of Mercury (Hg) or 14.96 psia
80 degrees fahrenheit is the equivalent of
26.7 degrees celsius
22 degrees celsius is the equivalent of
71.6 degrees fahrenheit
To change from psig to psia you must:
add 14.96 to psig
A barometer is used to measure ________ pressure
atmospheric
How much pressure is exerted downward by a 50-pound solid object that has a base area of 10 square inches?
5 psi
What is the formula for finding pressure?
pressure = force/area
If a 100lb solid object exerts a downward force of 200 psi, what is the area of the object’s base?
Area= force/pressure 200/100= 0.5square inches
The three types of heat transfer?
conduction, convection, radiation
Sensible heat is described as a change in _______
temperature
Latent heat is described as a change in ______
state
