ac test 1

because sunlight is essential for the formation of stratospheric ozone, it is formed mainly over what region of the globe ?

the equator

what is a material called that can block the flow of heat?

an insulator

all of the following are processes by which heat

latent

in what year did the first production vehicle automotive air conditioning unit appear on the market

1940

All of the following are important properties that an automotive refrigerant must exhibit except:

A refrigerant must be explosive or flammable.

All of the following are forms of heat transfer that take place as it relates to the vehicle air-conditioning system except:

Perspiration

All of the follow are true about engine thermostats except:

The coolant hoses bursting due to air pressure.

all of the following are gas law, except

darwin's law

Tech A says the low-side gauge on the manifold gauge set is on the left and has green housing. Tech B says the high-side gauge on the manifold gauge on the left and has a red housing

neither A or B

what can ultraviolet radiation cause

skin cancer and damage to the eyes

A common engine thermostat has a temperature rating of:

195 Degree F

what is the air we breathe made up of

21 percent oxygen and 78 percent nitrogen

When the cooling system is placed under pressure, for each pound per square inch (psi) of cooling system pressure, the boiling point of the coolant is increased by:

3 Degree F

The acceptable comfort range for the human body is

72 - 80 F and 45- 50 percent relative humidity

A vehicle is in for repair with a complaint of poor heat output. During testing and diagnosis air is found to be trapped in the heater core. Which of the following is the most likely cause?

A faulty head gasket

In a normally operating system, the refrigerant is in different physical states (vapor or liquid) at the various sections of the system. All of the following are physical states the refrigerant would be found in at various specific locations except:

A high-pressure liquid at the condenser

Engine coolant loss could be caused by all of the following except:

A leaking transmission cooler line

If a thermostat fails in the open position, all of the following will occur, except:

A loss of engine coolant.

The metering device changes high-pressure liquid to

A low-pressure liquid

Electric cooling fans are being discussed: Technician A says that they are independent of the ignition switch and may start and run without notice at any time. Technician B says that they are generally protected by a shroud and pose no safety problem. Who is correct?

A only

Tech A says that a vacuum pump is used to remove moisture form a system. Tech B says that an air pump is used to remove air from a system.

A only

Tech A says that exhaust gases from internal combustion engines contain carbon monoxide gas. Tech B says that exhaust gases from internal combustion engines contain phonephone gas

A only

Tech A says that placing one foot behind the other braces oneself against a fall if the wrench slips while pulling. Tech B says that placing one foot in front of the other braces oneself if the wrench slip while pushing

A only

Tech A says that the english/metric measurement unit for pressure is psig/Kpa. Tech B says that the English/ metric measurement unit for temperature is Fahrenheit/ Centigrade.

A only

Tech A says that the repair order is a legal document that must filled out for every vehicle worked on Tech B says that a repair order does not need to filled out for a no charge (free) repair

A only

Technician A says that a slight temperature change at the inlet and outlet of the receiver-drier indicates a restriction. Technician B says that a slight temperature change at the inlet and outlet of an accumulator indicates a restriction. Who is correct?

A only

Technician A says that the blower should be run on high speed for the performance test. Technician B says it does not matter at what speed the fan is run. Who is correct?

A only

Technician A says that the maximum working pressure of service hoses should be 500 psig (3,448 kPa). Technician B says that 500 psig (3,448 kPa) is also the burst pressure. Who is correct?

A only

Technician A says the condenser is a heat exchanger for the superheated refrigerant in the system. Technician B says the accumulator is a heat exchanger that removes heat from the air flowing across the evaporator cooling fins. Who is correct?

A only

All of the following conditions could cause poor passenger compartment heating system performance except:

A thermostat stuck in the closed position.

Each type of refrigerant uses a unique set of service fittings that:

Are designed to prevent accidental mixing of refrigerants.

Tech A says that an OSHA is a state agency responsible for Occupational Standards for Heating and Ari Conditioning. Tech B says and OSHA poster must be displayed in the employees' common area, such as the break room

B only

Tech A says that you only need one manifold gauge set and it may be used for any type of refrigerant you need to service . Tech B says a vacuum pump is an essential piece of equipment for servicing a refrigerant system.

B only

Tech A says the wire harness, terminals, and connectors of the High-voltage system are identified by red. Tech B says to remove the service plug prior to disconnecting or reconnecting and High-voltage connections or components.

B only

Technician A says that a change in temperature from the inlet to the outlet of the thermostatic expansion valve (TXV) is not acceptable. Technician B says that a change in temperature from the inlet to the outlet of a fixed orifice tube (FOT) is acceptable. Who is correct?

B only

The tank on a radiator has ruptured: Technician A says that a thermostat that is stuck in the open position could be the cause. Technician B says that a faulty radiator cap could be the cause. Who is correct?

B only

Cooling system service is being discussed: Technician A says that ethylene glycol antifreeze must be disposed of in a manner prescribed by the Environmental Protection Agency (EPA) and local ordinances. Technician B says that after hoses have been replaced, clamp tension should be rechecked after the cooling system has been allowed to thermocycle. Who is correct?

Both A and B

Engine overcooling is being discussed: Technician A says that a thermostat stuck open could be the cause of this condition. Technician B says that a missing thermostat could be the cause of this condition. Who is correct?

Both A and B

Tech A says service information system may include estimating and shop management software. Tech B says service information you find on the internet contains both accurate and inaccurate information

Both A and B

Tech A says that a flare nut wrench may be used on a flare nut. Tech B says that an open-end wrench may be used on a flare nut.

Both A and B

Tech A says that safety glasses should be approved for gases. Tech B says that safety glasses should be approved for liquids.

Both A and B

Tech A says that you are entitled to a clean, safe palce to work . Tech B says as an employee your obligation is to be a loyal, caring individual, and have the ability to follow directions

Both A and B

Tech A says to lift heavy objects using the legs, not the back. Tech B says that one should get help when lifting heavy object.

Both A and B

Technician A says that a manifold and gauge set is one of the primary service tools for the air conditioning service technician. Technician B says that a manifold and gauge set must be dedicated to the type of refrigerant being serviced. Who is correct?

Both A and B

Technician A says that a manifold and gauge set must have service shut-off valves within 1 ft. (30 cm) of the hose service end. Technician B says that a recovery/recycling station must have service shut-off valves within 1 ft. (30 cm) of the hose service end. Who is correct?

Both A and B

Technician A says that antifreeze should be changed every 2 years. Technician B says that extended-life coolant may last up to 5 years. Who is correct?

Both A and B

Technician A says that as a neoprene serpentine belt ages and wears cracks will form on the belt ribs and that if there are more than three cracks in a 4-inch span, the belt should be replaced. Technician B says that serpentine belts made of EPDM resist cracking and instead exhibit wear to the belt ribs similar to tire wear, and that a depth gauge should be used to assess belt wear. Who is correct?

Both A and B

Technician A says that humidity has an effect on system performance. Technician B says that poor airflow has an effect on system performance. Who is correct?

Both A and B

Technician A says that the kPa scale is used to denote pressure on the metric gauges. Technician B says that the Hg/psig scale is used to denote pressure on the English scale. Who is correct?

Both A and B

Technician A says that the line or hose that connects the compressor outlet to the condenser inlet is called the discharge line. Technician B says that the line or hose that connects the evaporator outlet to the compressor inlet of a TXV system is called a suction line. Who is correct?

Both A and B

Technician A says that the performance test determines if system pressures are proper. Technician B says that the test determines if the system temperatures are proper. Who is correct?

Both A and B

Technician A says that when pressure testing a cooling system, it should hold pressure for 5 minutes. Technician B says that a wet carpet may indicate a heater core leak. Who is correct?

Both A and B

Technician A says the compressor is one of the points in the air-conditioning system where there is a separation between a high and a low pressure. Technician B says the metering device is one of the points in the air-conditioning system where there is a separation between a high and a low pressure. Who is correct?

Both A and B

The shop's safety program is being discussed. Tech A says that the program will ineffective if the technician does not work with care. Tech B says that the program will be ineffective if the rules are not observed

Both A and B

Tool quality isi being discussed. Tech A says that mechanics' tools should be made of alloy steel. Tech B says that mechanics' tools should be tempered

Both A and B

tech A says that chlorine (Cl), and ingredient of CFC refrigerants, is harming the ozone layer. Tech B says that the ozone layer is important for pro tection from ultraviolet (UV) radiation. who is correct?

Both A and B

The most likely use for an engine coolant temperature switch is to electrically energize the:

Cooling system fan motor

All of the following statements about engine cooling systems are true EXCEPT:

It is ok for a technician to install a thermostat with a low temperature rating than the original thermostat.

The least likely problem associated with a cooling system that had the thermostat removed is:

Loss of coolant

Engine coolant is designed to provide all of the following except:

Lower the boiling point of the solution.

Tech A says that ethylene glycol is essentially a nontoxic anti-freeze and hence is sager for children and animals. Tech B states that toxicologists report that polypropylene glycerol inside the body is changed into a crystalline acid that attacks the kidneys

Neither A and B

An overheating condition is being discussed: Technician A says that replacing the thermostat with one of a lower temperature rating will reduce the coolant temperature. Technician B says that replacing the pressure cap with one of a lower rating will reduce the coolant temperature. Who is correct?

Neither A nor B

Coolant loss is being discussed: Technician A says that a missing thermostat could be the problem. Technician B says a heater control valve stuck open may be the problem. Who is correct?

Neither A nor B

Technician A says that an R-12 manifold and gauge set may be used on an R-134a system. Technician B says that an R-134a manifold and gauge set may be used on an R-12 system. Who is correct?

Neither A nor B

Technician A says that the low-side gauge may be used on the high side, if necessary. Technician B says that the high-side gauge may be used on the low side, if necessary. Who is correct?

Neither A nor B

Technician A says the fixed orifice tube can vary the amount of refrigerant allowed to flow to the evaporator. Technician B says the thermostatic expansion valve has a fixed opening and cannot vary the amount of refrigerant allowed to flow to the evaporator. Who is correct?

Neither A nor B

A vehicle is driven for 15-20 miles and the vehicle's passenger compartment blower motor continues to blow cold air. What is the most likely cause of this condition?

Partially restricted heater core

All of the following may cause the back side of a serpentine belt to separate except:

Pulley misalignment

R-134a, when used as a refrigerant, exhibits a predictable relationship between pressure and temperature, and a stable change of state point between a liquid and a gas under various pressures and temperatures. All of the following are true of the temperature pressure relationship of R-134a except:

Refrigerant in the liquid state can make a change of state to a gas (vapor) by increasing the pressure on the refrigerant without changing its temperature.

Under normal operating conditions all of the following occurs inside the evaporator, except:

The refrigerant changes from a vapor to a liquid.

All of the following statements about a Schrader-type service valve are correct, except:

The valve may be front seated.

All of the following are the function of the radiator pressure cap except:

To lower the freeze point of the coolant.

Tech A says that latent heat is hidden heat and connot be measured on a thermometer. Tech B says that latent heat is hidden heat that is required for a change of the state of matter.

both A and B

Tech A says that rules are made to protect the customer Tech B says that rules are made to protect the technician.

both A and B

Tech A says to determine the type of refrigerant use in the system, a refrigerant identifier should be used prior to servicing the vehicle's refrigerant system. Tech B says that when working on a refrigerant system you should work in a well ventilated area.

both A and B

heat transfer is being discussed: Tech A says that heat flows from a hot surface to a surface containing less heat. Tech B says that heat leaves the body by the process of evaporation.

both A and B

what is the main source of ozone-depleting chlorine in the stratosphere?

chlorine contained in chlorofluorocarbons

all of the following are factors that affect body comfort except:

concentration

what type of heat transfer requires air movement

convection

all of the following statements are true concerning high_voltage system safety, Except

disconnect the motor generators prior to turning the ignition off

Air conditioning is the process by which air is

heated, cooled, cleaned or filtered

in the greenhouse effect what type of radiation is re-emitted by the earth's surface and is absorbed and reflected by greenhouse gas molecules in th atmosphere warming the earth's surface and lower atmosphere?

infrared

the heat added to a vapor causing it to become warmer is called what ?

sensible and superheat

the hole in the ozone layer was detected over what region of the globle

south pole

everything in nature contains what type of heat

specific heat

we are concerned about ozone depletion in what layer of the atmosphere

stratosphere