NATE A/C Exam 2022/2023 with 100% correct answers

The Fahrenheit scale is based on boiling water at sea level at what temperature? A: 459 degrees B: 212 degrees C: 180 degrees D: 100 degrees B: 212 degrees Zero pounds gauge corresponds on the absolute scale to: A: 144 B: 212 C: 14.7 D: zero C: 14.7 Hidden heat in refrigeration work is referred to as: A: Intensity of heat B: Latent heat C: Heat a thermometer can "sense" D: Cold B: Latent heat Absolute zero on the Fahrenheit scale is: A: 459 degrees B: 273 degrees C: 100 degrees D: 0 degrees A: 459 degrees A ton of refrigeration is a unit equal to: A: 2,880,000 btu per day B: 12,000 btu per hour C: 2,000 btu per minute D: All of these are correct B: 12,000 btu per hour The heat used to change a liquid to a gas is called the latent heat of: A: Absorption B: Vaporization C: Fusion D: Liquid B: Vaporization A thermometer is said to "sense" what? A: Heat of fusion B: Latent heat C: Sensible heat D: Specific heat C: Sensible heat Five pounds of water is heated by two degrees F. How many btu were added to the water? A: 25 btu B: 10 btu C: 5 btu D: 2 btu B: 10 btu Wght x deg raise = btu's 5 x 2 = 10 btu's The amount of heat required to melt one pound of ice at 32 degrees F is: A: 212 btu B: 180 btu C: 144 btu D: 970 btu C: 144 btu Superheat is added: A: In changing a liquid to a vapor B: In raising the temperature of water C: After all the liquid has been changed to vapor D: None of these is correct C: After all the liquid has been changed to vapor Subcooling is: A: Heat removed in changing the temperature of a liquid. B: Heat which causes a liquid to turn into a solid C: Heat removed from a liquid below 0 degrees F D: Heat removed below the subheat temperature A: Heat removed in changing the temperature of a liquid. The saturation temperature is: A: Never actually reached B: When water is at 0 degrees F C: The same as the condensing temperature and boiling temperature D: The reciprocal of the inverse of the superheat ratio C: The same as the condensing temperature and boiling temperature Cold is: A: Any temperature below 98.6 degrees F B: A temperature lower than 50 degrees F C: A relative term with no specific temperature D: A temperature near absolute zero C: A relative term with no specific temperature As the pressure over a liquid is lowered, _____________________. A: temperature decreases B: temperature increases C: the boiling point of the liquid increases D: the boiling point of the liquid decreases D: the boiling point of the liquid decreases As heat is added to a substance, _________________. A: the molecules move slower B: it becomes even easier to add still more heat C: the substance loses heat D: the molecules move faster D: the molecules move faster The amount of heat it takes to change the temperature of one pound of a substance by one degree Fahrenheit is called: A: Subcooling B: Specific heat C: Superheat D: Specific density B: Specific heat The specific heat of a substance changes when: A: The temperature is greater than 100 degrees B: The substance changes weight C: The temperature falls below 30 degrees D: The substance changes state D: The substance changes state A half-filled cylinder of refrigerant at 80 degrees F will be: A: Superheated B: Sub-cooled C: Saturated D: Sub-heated C: Saturated The air you are breathing is: A: Super-heated B: Sub-cooled C: Saturated D: Sub-heated A: Super-heated The three methods of heat transfer are: A: Conduction, convection and radiation B: Conduction, convection and evaporation C: Condensation, convection and radiation D: Convection, radiation and sublimation A: Conduction, convection and radiation As a gas is compressed, _____. A: temperature and pressure increase B: pressure decreases and volume increases C: temperature decreases and pressure increases D: temperature and pressure decrease A: temperature and pressure increase When compressed enough and then cooled, a gas will: A: Explode B: Sublimate C: Flame off D: Condense D: Condense The condensing temperature and the _____ temperature mean the same thing. A: superheated B: subcooling C: saturation D: sublimated C: saturation The evaporator is a: A: High pressure component B: Low pressure component C: High and low pressure component D: None of these is correct B: Low pressure component The two components that contain coils are: A: Condenser and compressor B: Condenser and evaporator C: Evaporator and compressor D: Evaporator and accumulator B: Condenser and evaporator Refrigerant vaporizes in the: A: Condenser B: Evaporator C: Compressor D: Oil separator B: Evaporator The two components that divide the high pressure side from the low pressure side of a system are the: A: Compressor and condenser B: Compressor and metering device C: Condenser and evaporator D: Liquid line and suction line B: Compressor and metering device The pipe which connects the evaporator to the compressor is the: A: Suction line B: Liquid line C: Discharge line D: Hot gas line A: Suction line The pipe which connects the compressor to the condenser is the: A: Suction line B: Liquid line C: Discharge line D: Hot gas line C: Discharge line Which one of the following refrigerants would be used with POE oil? A: R22 B: R12 C: R502 D: R410A D: R410A The discharge line temperature of a reciprocating compressor should never be allowed to exceed how many degrees F? A: 190 degrees B: 225 degrees C: 325 degrees D: 375 degrees B: 225 degrees Refrigerant becomes superheated in the: A: Evaporator B: Evaporator and suction line C: Evaporator, suction line and compressor D: Bottom of the condenser C: Evaporator, suction line and compressor Refrigerant is in its saturated state in the: A: Compressor B: Liquid line C: Condenser D: Suction line C: Condenser The temperature-pressure chart works: A: Where refrigerant is saturated B: Where refrigerant is superheated C: Where refrigerant is subcooled D: Wherever the manifold gauges are attached A: Where refrigerant is saturated Which service valve should never be front-seated while the compressor is operating? A: Compressor suction service valve B: Compressor discharge service valve C: King valve D: Schrader valve B: Compressor discharge service valve