Quiz 6 Flashcards
The Fahrenheit scale is based on boiling water having a sea level temperature of?
212
Zero pounds gauge pressure corresponds to an absolute scale reading of?
14.696
Hidden heat in refrigeration work is referred to as?
Latent heat
Absolute zero on the Fahrenheit scale equals?
-460
The heat used to change a liquid to a gas is called the latent heat of?
Vaporization
A thermometer is used to measure?
Sensible heat
Which of the following causes a change of state of a substance?
Latent heat
Heat transfer flows from a material at a higher temperature to a lower temperature
True
The amount of heat required to raise the temperature of one pound of a substance one degree Fahrenheit is?
Specific heat
Convert 75 degrees Celsius to Fahrenheit
F = (1.8 x C) + 32
167 F
Convert 87 degrees Fahrenheit to Celsius
C = .555 x (F -32)
30.525 C
Convert -40 degrees Celsius to Fahrenheit
F = (1.8 x C) + 32
-40 F
Heat being a form of energy cannot be ________
Destroyed
Ice will begin to melt when it’s sensible temperature rises above
32 F
Name the three states most elements and compounds may exist in
Solid, gas, liquid
The device/unit used to measure the quantity of heat is the
BTU
The instrument used to measure the intensity or level of heat is called
Thermometer
Heat transfer will exist between two objects of the same temperature
False
The boiling point of water on the Celsius scale at sea level is
100 C
Atmospheric pressure would be greater on a mountain top compared to its pressure at seal level
True
Approximately how many inches of mercury are equal atmospheric pressure at sea level under standard conditions
29.92 in HG
Definition of a substance that takes up space and has weight
Matter
In which direction does a solid exert pressure
Downward
In which direction does a liquid exert pressure
Downward and outward
In which direction does a gas exert pressure
All directions
Heat is considered a form of energy
True
Magnetism is considered a form of energy
True
Electricity is purchased from the utility company and measured by the
Kilo-hour
One kilowatt (KW) equals _____ BTUs
3413
How many watts of electrical energy equals one horsepower
746
There are three quantities needed to determine horsepower. They are weight/force, distance, and _____
Time
Referring to manifold gauges, the low side gauge divisions are calculated in
Five pound increments
Also referring to manifold gauges, the high side gauge division are calibrated in
Five pound increments
This gauge reads pressures above and below atmospheric pressure
Low sided gauge
Bonus. It would take ________ horsepower motor to lift a 2000 pound condensing unit 30 feet in 30 seconds
Force = Mass x Acceleration (32.2 ft/s)
2000 x 32.2 = 64400 lb ft/s
64400 x 30 ft = 1932000 lb ft
Work = 1932000
Time = 30 seconds
HP = 1932000 / (30s x 550)
HP = 117.85
