問題一覧
1
Which of the following statement is NOT true?
When heat is added to a substance its temperature always rises
2
The amount of heat (measurein btu's) that is required to raise the temperature of one pound of substance 1 degree F is referred to as
Specific heat
3
Matter exist in three states and its mass?
never changes
4
When soldering an electrical connection with a soldering iron, the method of heat transfer being utilized is
Conduction
5
In the diagram above which points represent where the latent heag process is taking place?
B to C and D to E
6
Dry Ice is actually made from
carbon dioxide
7
The result of applying a force through a distance is termed as
Work
8
Temperature is defined as
the level or intensity of heat
9
______ heat transfer can be explained aa the energy actually traveling from one molecule to another
Conduction
10
In theory molecular motion stops at
0 degrees Rankine
11
Convert -37 dg C to degrees Fahrenheit
-34.6 deg F
12
Which of the following btu ratings correctly describes one ton of refrigeration
all of the above
13
One British Thermal Unit will raise the temperature of ____ LB of water _____ deg F
1 & 1
14
Given two objects of the same size, one chrome painted and one painted black, which of the two will absorb more radiant heat?
Black painted object
15
Which of the following has the largest specific heat capacity
Water
16
Conductivity is the
a substances ability to conduct heat
17
Using the formula Q = MC(T2-T1), what amount of heat would need to be removed to cool 120 lb of vegetable oil from 95 deg F to 45 deg F if the specific heat of the oil is .4 btu/lb
2400 btu's
18
Convert 45 deg F to deg Celsius
7.2 deg C
19
The temp. difference multiplied by the number of pounds of water will give?
number of BTU
20
Which of the following units is used to express the quantity of heat in a substance in the metric system?
Kilojoule
21
Sensible heat, latent heat and total heat are all different forms of heat.
True
22
The latent heat of fusion describe a change in state from a
solid to a liquid
23
A rise in sensible heat causes
a rise in temperature on a thermometer
24
Heat conduct at the same rate in all materials.
False
25
The temperature at which a liquid will boil is dependant upon the pressure exerted on the surface of the luquid.
True
26
Will glass or copper conduct heat the most rapidly
Copper
27
What is the heat content for only the "latent heat of Evaporation" process, if 1 lb of ice at 0 deg F is turned into 1 lb of steam at 212 deg F
970 BTU's
28
The highgest temperature at which a substance may be liquefied regardless of the pressure applied upon it is referred to as
Critical temperature
29
The component in a refrigeration system where the refrigerant boils and absorbs heat is referred to as the;
Evaporator
30
Refrigerant fluids are
all of the above
31
Latent heat causes
a change of state in a substance
32
Heat will flow in what direction
Warm to cold
33
What does the sensing bulb of a thermostatic expansion valve sense
The temperature of the refrigerant at the outlet of the evaporator
34
What is the new temp. of 50 lbs of water at 180 deg F if the total heat removed is 4000 BTU?
100 F
35
Heat that is given by an infra red heater is an example of which heat transfer method
Radiation
36
What is the heat content required to change 10 lbs of ice at 32 deg F to 10 lbs of water at 32 deg F
1440 BTU
37
The method of heat transfer that is known "Hidden Heat" is really
latent heat
38
40 deg Kelvin would equal which of the following
-388 deg F
39
Which of the following heat transfer methods best describe the principle of convection?
Movement of heat by air or fluid
40
The four absolute temperature scales begin at which of the 4 corresponding temperatures
-460 F, -273 C, 0 deg R, 0 K