Unit 1 Flashcards
Convert 150°F to Celsius
65.56 C
0 C converted into Fahrenheit
32 F
-30 C converted into Fahrenheit
-22 F
350 C converted into Fahrenheit
662 F
Which temperature is the hottest?
A. 600R
B. -20C
C. 150F
D. 380k
D. 380K
-400 F converted into Celsius
-240 C
True or False
Latent heat is also known as hidden heat because it can’t be measured.
True
True or false
The Uninsulated portion of the suction line should be warm and dry.
False it should be cold and sweaty
True or false
Specific heat is the amount of heat necessary to raise the temperature of one pound of water 1 F.
False (1lb of any substance)
True or false
As you gain elevation/altitude, atmospheric pressure decreases.
True
True or false
A compound pressure gauge reads pressure above and below atmospheric pressure.
True
True or false
System superheat is measured by placing a thermocouple on the suction line right before it enters the compressor.
True
True or false
The instrument that measures atmospheric pressure is called the Bourdon tube.
False
True or false
Pressure is defined as force per unit of area
True
True or false
When water at 212 F boils, it is only absorbing latent heat.
True
The two common temperature scales used by air conditioning and refrigeration technicians are called _______ and _________
- Fahrenheit scale
- Celsius scale
Heat that changes the temperature of a substance is called ________ heat.
Sensible
Convert psig to psia
325 psig
339.70 psia
Convert psia into psig
235 psia
220.304 psig
Convert inches of HG (mercury) vacuum to psia
15 in HG
7.5 psia
Convert HG to psia
6in HG
12 psia
Gauge that can read pressures above and below atmospheric pressure.
Compound gauge
Energy traveling from one molecule to another within a substance.
Conduction
Instrument used to measure atmospheric pressure.
Barometer
Absolute scale of Fahrenheit.
Rankine scale
Level of heat.
Temperature
14.696 psi at sea level.
Standard condition
Gaseous state of a substance.
Vapor
Movement of molecules within a substance.
Molecular motion
Amount of energy required to change a substance into a vapor.
Latent heat of vaporization
As the temperature of a material increases, the molecules in the material _______.
A. Stop moving
B. Travel faster
C. Slow down
D. Travel in more of a parallel direction
B. Travel faster
True or false
Silicone elastomers, used in seals and gaskets, are not compatible with HFO refrigerants.
True
What should be used to remove ice from sight glasses or viewing glasses?
Alcohol Spray
Persons who maintain, service, repair or dispose of appliances containing more than 5 lbs of refrigerant, or if the installation of such equipment requires refrigerant charging, must be certified as Type ____ technicians.
Type 2
De-superheating takes place in what basic component of the refrigeration system?
Condenser
In order for a pound of 60 F water to boil, how many btus of heat must be added to it?
152BTUs
What do the inner rings of numbers and different colors of an analog manifold gauge indicate?
Outter ring = Pressure
Colors = Refrigerants
Numbers = Temperature
IN __________ HEAT OR HIDDEN HEAT, HEAT IS KNOWN TO BE ADDED, BUT NO TEMPERATURE RISE IS NOTICED.
LATENT
IN __________ HEAT OR HIDDEN HEAT, HEAT IS KNOWN TO BE ADDED, BUT NO TEMPERATURE RISE IS NOTICED.
LATENT
PSIA AT SEA LEVEL UNDER STANDARD CONDITIONS IS ________________________
14.696 PSIA OR 29.92 IN. Hg
THE TWO COMMON TEMPERATURE SCALES USED BY AIR CONDITIONING AND REFRIGERATION TECHNICIANS ARE CALLED
FAHRENHEIT AND CELSIUS
THE FAHRENHEIT ABSOLUTE SCALE IS CALLED THE
RANKINE SCALE
ATMOSPHERIC PRESSURE IN INCHES OF MERCURY (Hg) DECREASES ___________ PER 1000 FT INCREASE
1 IN. Hg
A GAUGE THAT READS 0 PSI WHEN OPENED IN THE ATMOSPHERE ARE KNOWN AS ________________ GAUGE
COMPOUND GAUGE OR HIGH SIDE GAUGE
THE CELSIUS ABSOLUTE SCALE IS CALLED THE ___________ SCALE.
KELVIN
THE WEIGHT OF A COLUMN OF AIR AT SEA LEVEL AT STANDARD CONDITIONS IS
14.696
HEATING THE VAPOR TEMPERATURE ABOVE THE BOILING POINT IS CALLED
LATENT HEAT OF VAPORIZATION OR SUPERHEAT
HEAT THAT CHANGES THE TEMPERATURE OF A SUBSTANCE IS CALLED
SPECIFIC HEAT
WHAT IS THE DIFFERENCE BETWEEN A MERCURY BAROMETER AND AN ANEROID BAROMETER?
MERCURY BAROMETER USES MERCURY TO MEASURE ATMOSPHERIC PRESSURE
ANEROID BAROMETER USES AIR TO MEASURE ATMOSPHERIC PRESSURE
HOW MANY BTUS OF HEAT ARE REMOVED PER HOUR WHEN THE WATER AT A FLOW RATE OF 10 GALLONS PER MINUTE IS COOLED 15F? (WATER WEIGHS 8.33 LBS. PER GALLON)
74,970 BTU/HR
DEFINE CONDUCTION OF HEAT
HEAT TRANSFER BETWEEN MOLECULES THROUGH DIRECT CONTACT
DEFINE RADIATION OF HEAT
THE TRANSFER OF THERMAL ENERGY THROUGH ELECTROMAGNETIC WAVES
HOW MANY BTUS ARE REQUIRED TO CHANGE ONE POUND OF ICE AT 20°F to steam at 220°F
1,304 BTUS/H
THE STANDARD ATMOSPHERIC PRESSURE AT SEA LEVEL IS
29.92 “ Hg
WHICH OF THE FOLLOWING REPRESENTS A DIFFERENT TEMPERATURE THAN THE OTHER THREE?
15 DEGREES CELSIUS
HOW MANY BTUs ARE REQUIRED TO CHANGE 5 POUNDS OF ICE AT 20F TO STEAM AT 220F?
6,520 BTU/H
TEMPERATURE CAN BE THOUGHT OF AS
DESCRIPTION OF THE LEVEL OF HEAT
PURE WATER BOILS AT A TEMPERATURE OF 212F AT WHICH OF THE FOLLOWING IS STANDARD CONDITIONS?
14.696 PSI
AS THE TEMPERATURE OF A MATERIAL INCREASES, THE MOLECULES IN THE MATERIAL
TRAVEL FASTER
HOW MANY BTUs MUST BE REMOVED FROM ONE POUND OF WATER AT 200F FOR IT TO END UP AS ICE AT 30F?
313 BTU
THE TEMPERATURE ON THE CELSIUS SCALE WHERE ALL MOLECULAR ACTIVITY STOPS IS
-273C
THE AMOUNT OF HEAT NEEDED TO CHANGE THE TEMPERATURE OF A SUBSTANCE WILL VARY WITH THE TYPE OF SUBSTANCE. THIS HEAT QUALITY IS CALLED THE _________ OF THE SUBSTANCE.
SPECIFIC HEAT
THE TEMPERATURE OF THE FAHRENHEIT SCALE WHERE ALL MOLECULAR BIOLOGY ACTIVITY STOPS IS
-460F
THE CELSIUS EQUIVALENT OF 80F IS
26.7C
AT STANDARD CONDITIONS ON THE CELSIUS SCALE, WATER WILL BOIL AT
100C
OF THE FOLLOWING CHOICES, THE WARMEST TEMPERATURE IS
303K
PSIG INDICATES
POUNDS PER SQUARE INCH GAUGE
A BOURDON TUBE IS OFTEN FOUND IN A(N)
PRESSURE GAUGE
