HAC-101 Chap 58 Principles of HVAC Test B

Air conditioning systems absorb heat from a cab interior through a(n)

• a. Condenser

• b. Evaporator

• c. Compressor

• d. Blower

How do the late-model vehicles help maintain a cleaner and dust-free cab interior?

• a. Equipped with an air ventilator located at the cab air inlet

• b. Equipped with an air filter located at the cab air inlet

• c. Equipped with an air compressor located at the cab air inlet

• d. Equipped with an air filter located at the cab air outlet

Moisture condensed on a cold _______ helps remove dirt and other particulates.

• a. Condenser

• b. Evaporator

• c. Compressor

• d. Ventilator

Which measurement of heat best describes the quantity of heat required to produce a change of state from a solid to a liquid or a liquid to a gas?

• a. Latent heat

• b. Radiant heat

• c. Specific heat

• d. Sensible heat

Heating is regulated by circulating engine coolant through an in-cab heat exchanger called a

• a. Radiator core

• b. Heat core

• c. Condenser

• d. Pressure control switch

Technician A says removing heat from an object or substance is simple, because cold always moves toward a warmer object. Technician B says all that is necessary for cooling is to provide an even warmer substance for cold to flow into. Who is correct?

• a. Technician A

• b. Technician B

• c. Both Technician A and Technician B

• d. Neither Technician A nor Technician B

Which of the following holds true for refrigeration systems?

• a. They add moisture to the air passing through the evaporator.

• b. The compressor is an engine-driven pump that decreases refrigerant pressure.

• c. Air conditioning and refrigeration systems transfer heat from the cab and passenger compartment to the air stream outside the vehicle.

• d. The refrigeration system operates in an open loop.

The thermal expansion valve device lowers the pressure of the warm, high-pressure liquid refrigerant entering the

• a. Evaporator

• b. Condenser

• c. Compressor

• d. Orifice

Which of these holds true for H-Valve thermal expansion valve (TXV) operation?

• a. TVX meters the refrigerant into the evaporator at a variable rate.

• b. It maintains the evaporator at low temperature and pressure.

• c. Spring tension acting on the orifice ball regulates the quality of refrigerant flow.

• d. Inlet temperature also can change the position of the linkage.

The coldest air temperature from the evaporator is when the blower is operated at its

• a. Molecular

• b. Slowest

• c. Fastest

• d. Road