HAC 105 Final

The difference between absolute pressure and gauge pressure is ____.

14.7 psi

The principles of ____ law are demonstrated when temperature remains constant, but pressure and volume express an inverse relationship.

Boyle's

The principles of ____ law are demonstrated when pressure remains constant, but temperature and volume rise and fall together.

Charles'

Based on ASHRAE Standard 34, which refrigerant classification would indicate least toxicity?

Class A1

To determine the total pressure of a mixture of gases, ______________________________ law states that the pressure for each gas must be added.

Dalton's

When air is trapped in an HVAC system's condenser, high-side pressure readings will be affected by the principles of ____ law.

Dalton's

A superheated vapor contains some refrigerant in liquid form.

False

Refrigeration systems that use capillary tubes as refrigerant metering devices must have a liquid receiver in order to work properly.

False

The principles of ____ law are demonstrated when volumes remains constant, but pressure and temperature rise and fall together.

Gay-Lussac's

Fluids that are used to boil and absorb heat are called refrigerants.

True

Electrical shock occurs when ____.

a body becomes part of an electrical circuit

A vapor refrigerant is superheated if its temperature is ____ the refrigerant's boiling point

above

Low-pressure refrigerant has the potential to ____ heat.

absorb

Always use a pressure regulator when working with ____.

all of the above

Before operating a power tool, ____.

all of the above

Concerning pressure, volume, and heat, if energy is added to a substance, then ____.

all of the above. volume may increase. temperature may increase. pressure may increase

Name three main HVACR system components located on the low-pressure side.

evaporator. accumulator. suction line filter-drier. suction line

A hard hat can be worn with the bill facing forward or backward.

false

A ladder can be placed on a scaffold as long as the scaffold wheels are locked.

false

A liquid line filter-drier is installed in the low side of the system.

false

A perfect vacuum is 0 psig.

false

A reciprocating compressor uses one or more pistons that move in only one direction.

false

A stationary refrigerant detector indicates when refrigerant is moving too slowly in a system.

false

Boyle's law states that the pressure of a gas increases if its volume also increases.

false

IN an emergency situation, any type of fire extinguisher can be used on any type of fire.

false

Keys used for electrical lockout must be kept near the lockout device so any worker can unlock the device in an emergency.

false

Like gases, solids and liquids are compressible in most cases.

false

Refrigerant in the form of low-pressure vapor has the highest capacity to absorb heat.

false

Suction lines are generally smaller in diameter than liquid lines

false

Tagout is the practice of securing an electrical switch in an open position so a circuit cannot be energized while work is being performed.

false

You can safely use water to extinguish an electrical fire.

false

The instantaneous evaporation of liquid refrigerant when it enters the evaporator is called ____.

flash gas

A condenser with a fan is called a(n) ______________________________ condenser.

forced-air

The Globally Harmonized System (GHS) includes the following standard label elements except ____.

foreign language translations

As a gas is compressed into a smaller space, ____ the gas.

heat is added to

Which of the following is not a type of metering device used to control the flow of refrigerant?

hermetic float

Heat is rejected out of a refrigeration system on the ____ side of the system.

high

During normal operation, refrigerant pumped into a condenser is in the form of ____.

high-pressure vapor

Store and transport refrigerant cylinders ____.

in a vertical position with the valve up

Pressure below atmospheric pressure is primarily measured in ____.

inches of mercury

Small pressure above or below atmospheric pressure is primarily measured in ____.

inches of water column

A suction line should be ____ to prevent moisture in the air from condensing on the cold tubing.

insulated

In SI units, pressure above atmospheric pressure is primarily measured in ____.

kilopascals

The primary hazard in a confined space is ____.

limited airflow

The critical temperature of a substance is the highest temperature at which the substance may be in a ____ state, regardless of the pressure applied to it.

liquid

A compressor is designed to draw in ____ refrigerant from the evaporator.

low-pressure vapor

Name four main HVACR system components located on the high-pressure side.

oil separator. condenser. liquid receiver. liquid line. liquid line filter-drier

When positioning an extension ladder, the base can be no farther from the wall than ____ the supported height.

one quarter

When using a torch near combustible materials, always ____.

place a heat shield between the torch flame and the materials

A cooling effect is produced when refrigerant enters an evaporator due to ____.

pressure change

According to the pressure formula, if area increases, then ____.

pressure decreases

According to the pressure formula, if force increases, then ____.

pressure increases

When referring to the correct usage of a fire extinguisher, the letters P.A.S.S. stand for ____.

pull aim squeeze n sweep

As applied pressure is raised on water, its boiling point ____.

rises

OSHA's Hazard Communication Standard (HCS) requires manufacturers and distributors to provide ____ for the chemicals they supply.

safety data sheets (SDS)

Heat-related illness may produce the following signs except ____.

shivering

If applied pressure on a saturated vapor is decreased, then ____.

some liquid will evaporate

If applied pressure on a saturated vapor is increased, then ____.

some vapor will condense

The fins on an evaporator increase the ____ of the evaporator tubing, allowing increased heat transfer from the air to the tubing.

surface area

A gas expands to fill its container.

true

A small amount of oil circulating throughout a refrigeration system is generally considered acceptable.

true

Asbestos insulation, which may be found in old installations, contains fibers that can cause cancer if inhaled.

true

Facial hair can make a dust mask or respirator ineffective due to poor sealing.

true

OSHA is the national law that covers workplace safety.

true

Pressures below atmospheric pressure can be measured in inches of mercury column.

true

Safety glasses or other eye protection should be worn when performing any work.

true

When a fusible plug in a cylinder melts, all of the refrigerant is released from the cylinder.

true

Working in hot temperatures can cause your body to overheat.

true

Evaporative cooling systems rely on the cooling effect derived from a ____.

verbal exchange

As a substance is heated, its ____ tends to increase.

volume