Deck 35: Heating and Air-Conditioning Fundamentals

Question 1

The boiling point of water is ____ at sea level.

A)112⁰F
B)180⁰F
C)212⁰F
D)232⁰F

Answer 1

C

Question 2

The outside air temperature (OAT) sensor, sometimes called a(n) ____________________, is usually located in front of the condenser in the grille, where it is not affected by engine temperature.

Answer 2

ambient sensor

Question 3

Which of the following is MOST-Likely to be the primary refrigerant used going forward in an effort to battle climate change ?

A)R-12
B)R-1234YF
C)R-134A
D)R-22

Answer 3

B

Question 4

Before matter can actually change its state, extra heat is required. This additional heat is called ____.

A)radiation
B)sensible heat
C)solid heat
D)latent heat

Question 5

When pressure in an air-conditioning system rises too high, the low-pressure cutout switch will open the circuit to the magnetic clutch.

Question 6

All of the following statements are true EXCEPT:

A)the sunload sensor is located in the defroster outlet grille or on the dash.
B)the sunload sensor reacts to incandescent light or sunlight but not to fluorescent light.
C)the discharge duct temperature sensor is an NCT that provides the control module with the temperature of the air leaving the duct.
D)an interior temperature sensor is usually mounted in the defroster.

Question 7

____________________ is the process in which air inside of the passenger compartment is cooled, dried, and circulated.

Question 8

While having a discussion, Technician A says that heat is transferred by radiation. Technician B says that heat is transferred by evaporation. Who is correct?

A)A only
B)B only
C)Both A and B
D)Neither A nor B

Question 9

An engine cooling system operating at the correct temperature with a properly operating thermostat is necessary for the heater to be effective.

Question 10

The amount of energy it takes to raise water's temperature from freezing to boiling is much more than the amount of latent heat of vaporization (the amount of heat needed to make the water boil).

Question 11

Which of the following is LEAST-Likely to cause heat transfer?

A)Convection
B)Radiation
C)Evaporation
D)Humidity

Question 12

A saturated vapor is a liquid that is in contact with its vapor within an enclosed space.

Question 13

When moisture from steam condenses on a cool bathroom mirror, a vapor changes to a liquid. This is called ____________________.

Question 14

Heat that goes into matter and results in a temperature increase is called ____________________.

Question 15

A receiver/dryer is located on the ____________________ of the system, whereas an accumulator is located on the low side.

Question 16

All of the following statements are true EXCEPT:

A)from the compressor, the refrigerant is pumped through the discharge line to the condenser, located in front of the engine's radiator.
B)the condenser is a radiator for refrigerant.
C)the refrigerant's boiling temperature becomes lower when it is pressurized.
D)cooling the pressurized refrigerant in the condenser causes it to change from a gas to a slightly cooled but still warm liquid.

Question 17

Low humidity (dry air) permits heat to be taken away from the human body by evaporation of perspiration.

Question 18

The part that is MOST-Likely to have multiple cylinders with pistons and one eccentric crankshaft throw called a Scotch yoke is the:

A)radial compressor
B)scroll compressor
C)displacement compressor
D)wobble plate

Question 19

While having a discussion, Technician A says a typical GM vehicle air conditioner is rated at about 5,000 Btu. Technician B says that it is rated at about 10,000 Btu. Who is correct?

A)A only
B)B only
C)Both A and B
D)Neither A nor B

Question 20

The term MOST-Likely used to refer to temperatures that are above a liquid's boiling point is:

A)radiation
B)superheat
C)desiccant
D)latent heat

Question 21

What is the purpose of the metering device, sometimes called a thermostatic expansion valve (TXV), or a thermal expansion valve?

Question 22

Why do some air-conditioning systems have a muffler installed on the outlet of the compressor?

Question 23

What is the purpose of an ambient temperature switch and a low pressure cutout switch?

Question 24

What are the two basic functions that a receiver/dryer and an accumulator share?

Question 25

What are the two principles of convection?