NATE CORE STUDY GUIDE (AWESOME) | COMPLETE QUESTIONS
WITH 100% ANSWERS | 2025 LATEST UPDATED!!
Which of the following is not the product of incomplete combustion: - (answers)Oxides of
nitrogen
An oil trap is required at the base of the discharge line of the vertical riser is _____ or above -
(answers)8 feet
A diode allows current to flow in one direction: - (answers)True
1 Watt = _____ Btu - (answers)3.41
Current in a closed circuit is limited by which of the following: - (answers)resistance
An oil separator is located in the _____: - (answers)Discharge line
______ is the heat that is absorbed or extracted when a substance changes its state: -
(answers)Latent heat
_______ is the temperature at which oil starts to produce a waxy substance that may interfere
with the refrigeration system: - (answers)Floc Point
1 kWh of electric power is equivalent to ______ Btu per hour: - (answers)3412
What will be the resistance in the circuit if the supply voltage is 30V and current flowing through
the circuit is 5A: - (answers)6 OHM
Gas valves operate at _____ voltage: - (answers)24V
_______ use two special helical rotors that introduce suction vapors then compress them: -
(answers)Screw Compressor
,A high pressure steam boiler operates at a pressure greater than ______ : - (answers)15 PSIG
In Fire tube boiler, which of the following pass through the tubes: - (answers)Flue Gas
1 kilo watt = ______ Btu - (answers)3140 BTU
Turning the TXV valve stem in _______ direction increases super heat: - (answers)Clockwise
Which of the following compressor uses pistons, cylinders and valves to compress the refrigerant
gas: - (answers)Reciprocating Compressor
Most of the heat transfer from the heat exchanger is by which of the following: -
(answers)Convection
Relays and contactors are ____ control switches: - (answers)Electrically Operated
Which of the following law states that the total pressure of a confined mixture of gases is the
sum of pressures of each of the gases in the mixture: - (answers)Daltons Law
At 32°F, 1 lb of ice can be changed to 1 lb of water by adding ____ Btu - (answers)144 BTU
Which of the following circuit does not have multiple paths for current flow: - (answers)series
Dual voltage three phase motor has _____ number of terminals - (answers)9
Which one of the following is known as the line that connects between the metering device and
the evaporator: - (answers)Inlet line
Approximately _____ voltage is required for creating a spark on a spark ignition system: -
(answers)15,000V
,Which one of the following in the refrigeration cycle changes the refrigerant from low pressure
gas to high pressure gas: - (answers)Compressor
Heat transfer that takes place in liquids and gases in which of the following: -
(answers)Convection
Which of the following is used to measure the pressure drop across the air filter: -
(answers)Manometer
What will be typical range of the current sensor: - (answers)4-20 mA
RTD which measure temperature have a positive temperature coefficient: - (answers)True
______ temperature is the temperature is the temperature below which moisture condense out of
air - (answers)Dew Bulb
Curved boundary In Psychrometric chart indicates which of the following: - (answers)Dew point
temperature line
_____ is a combination of both sensible heat and latent heat: - (answers)Enthalpy
The heat energy change that is associated with a change in the phase (state) is: - (answers)Latent
Heat
In water-tube boilers, pressures range from ______ : - (answers)50 to 5,000 psig
Which one of the following is used in systems for pressurizing the building: - (answers)Exhaust
or relief dampers
The temperature-resistance characteristic of a thermistor is _________ : - (answers)Non linear
At _________ this superheated refrigerant vapor pressure and temperature is added: -
(answers)Compressor
, For every 1000 feet above sea level,the capacity of a natural gas furnace is de-rated by _______ -
(answers)4%
If the surrounding air is colder than the skin temperature, the body gains heat: - (answers)False
The power developed by the centrifugal pump is proportional to _________ its speed: -
(answers)CUBE
Mineral oils are not to be used with HFC alternate refrigerants: - (answers)True
Flue gas temperatures at which the high-efficiency furnaces operate typically is: - (answers)100
to 275 degrees
Which of the following type of controllers are used in HVAC applications: - (answers)PI
According to ASME, safety valve of the boiler should be tested for every _____ days: -
(answers)30
In Psychrometric ________ indicates which of the following: Dew point temperature line: -
(answers)Chart curve boundary
1 horsepower = _________ watts: - (answers)746
Dew point temperature is the temperature at which web bulb temperature is _________ the dry
bulb temperature: - (answers)Equal to
The speed of 4 pole motor is about ______ rpm: - (answers)1800
A suction line accumulator is used for which of the following purpose: - (answers)Prevent liquid
refrigerant from entering compressor
WITH 100% ANSWERS | 2025 LATEST UPDATED!!
Which of the following is not the product of incomplete combustion: - (answers)Oxides of
nitrogen
An oil trap is required at the base of the discharge line of the vertical riser is _____ or above -
(answers)8 feet
A diode allows current to flow in one direction: - (answers)True
1 Watt = _____ Btu - (answers)3.41
Current in a closed circuit is limited by which of the following: - (answers)resistance
An oil separator is located in the _____: - (answers)Discharge line
______ is the heat that is absorbed or extracted when a substance changes its state: -
(answers)Latent heat
_______ is the temperature at which oil starts to produce a waxy substance that may interfere
with the refrigeration system: - (answers)Floc Point
1 kWh of electric power is equivalent to ______ Btu per hour: - (answers)3412
What will be the resistance in the circuit if the supply voltage is 30V and current flowing through
the circuit is 5A: - (answers)6 OHM
Gas valves operate at _____ voltage: - (answers)24V
_______ use two special helical rotors that introduce suction vapors then compress them: -
(answers)Screw Compressor
,A high pressure steam boiler operates at a pressure greater than ______ : - (answers)15 PSIG
In Fire tube boiler, which of the following pass through the tubes: - (answers)Flue Gas
1 kilo watt = ______ Btu - (answers)3140 BTU
Turning the TXV valve stem in _______ direction increases super heat: - (answers)Clockwise
Which of the following compressor uses pistons, cylinders and valves to compress the refrigerant
gas: - (answers)Reciprocating Compressor
Most of the heat transfer from the heat exchanger is by which of the following: -
(answers)Convection
Relays and contactors are ____ control switches: - (answers)Electrically Operated
Which of the following law states that the total pressure of a confined mixture of gases is the
sum of pressures of each of the gases in the mixture: - (answers)Daltons Law
At 32°F, 1 lb of ice can be changed to 1 lb of water by adding ____ Btu - (answers)144 BTU
Which of the following circuit does not have multiple paths for current flow: - (answers)series
Dual voltage three phase motor has _____ number of terminals - (answers)9
Which one of the following is known as the line that connects between the metering device and
the evaporator: - (answers)Inlet line
Approximately _____ voltage is required for creating a spark on a spark ignition system: -
(answers)15,000V
,Which one of the following in the refrigeration cycle changes the refrigerant from low pressure
gas to high pressure gas: - (answers)Compressor
Heat transfer that takes place in liquids and gases in which of the following: -
(answers)Convection
Which of the following is used to measure the pressure drop across the air filter: -
(answers)Manometer
What will be typical range of the current sensor: - (answers)4-20 mA
RTD which measure temperature have a positive temperature coefficient: - (answers)True
______ temperature is the temperature is the temperature below which moisture condense out of
air - (answers)Dew Bulb
Curved boundary In Psychrometric chart indicates which of the following: - (answers)Dew point
temperature line
_____ is a combination of both sensible heat and latent heat: - (answers)Enthalpy
The heat energy change that is associated with a change in the phase (state) is: - (answers)Latent
Heat
In water-tube boilers, pressures range from ______ : - (answers)50 to 5,000 psig
Which one of the following is used in systems for pressurizing the building: - (answers)Exhaust
or relief dampers
The temperature-resistance characteristic of a thermistor is _________ : - (answers)Non linear
At _________ this superheated refrigerant vapor pressure and temperature is added: -
(answers)Compressor
, For every 1000 feet above sea level,the capacity of a natural gas furnace is de-rated by _______ -
(answers)4%
If the surrounding air is colder than the skin temperature, the body gains heat: - (answers)False
The power developed by the centrifugal pump is proportional to _________ its speed: -
(answers)CUBE
Mineral oils are not to be used with HFC alternate refrigerants: - (answers)True
Flue gas temperatures at which the high-efficiency furnaces operate typically is: - (answers)100
to 275 degrees
Which of the following type of controllers are used in HVAC applications: - (answers)PI
According to ASME, safety valve of the boiler should be tested for every _____ days: -
(answers)30
In Psychrometric ________ indicates which of the following: Dew point temperature line: -
(answers)Chart curve boundary
1 horsepower = _________ watts: - (answers)746
Dew point temperature is the temperature at which web bulb temperature is _________ the dry
bulb temperature: - (answers)Equal to
The speed of 4 pole motor is about ______ rpm: - (answers)1800
A suction line accumulator is used for which of the following purpose: - (answers)Prevent liquid
refrigerant from entering compressor
