NATE CORE STUDY GUIDE 2024
questions with correct answers 100%
guaranteed
Which of the following is not the product of incomplete combustion: - answer Oxides of
nitrogen
An oil trap is required at the base of the discharge line of the vertical riser is _____ or
above - answer 8 feet
A diode allows current to flow in one direction: - answer True
1 Watt = _____ Btu - answer 3.41
Current in a closed circuit is limited by which of the following: - answer resistance
An oil separator is located in the _____: - answer Discharge line
______ is the heat that is absorbed or extracted when a substance changes its state: -
answer Latent heat
_______ is the temperature at which oil starts to produce a waxy substance that may
interfere with the refrigeration system: - answer Floc Point
1 kWh of electric power is equivalent to ______ Btu per hour: - answer 3412
What will be the resistance in the circuit if the supply voltage is 30V and current flowing
through the circuit is 5A: - answer 6 OHM
Gas valves operate at _____ voltage: - answer 24V
_______ use two special helical rotors that introduce suction vapors then compress
them: - answer Screw Compressor
,A high pressure steam boiler operates at a pressure greater than ______ : - answer 15
PSIG
In Fire tube boiler, which of the following pass through the tubes: - answer Flue Gas
1 kilo watt = ______ Btu - answer 3140 BTU
Turning the TXV valve stem in _______ direction increases super heat: - answer
Clockwise
Which of the following compressor uses pistons, cylinders and valves to compress the
refrigerant gas: - answer Reciprocating Compressor
Most of the heat transfer from the heat exchanger is by which of the following: - answer
Convection
Relays and contactors are ____ control switches: - answer 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: - answer Daltons Law
At 32°F, 1 lb of ice can be changed to 1 lb of water by adding ____ Btu - answer 144
BTU
Which of the following circuit does not have multiple paths for current flow: - answer
series
Dual voltage three phase motor has _____ number of terminals - answer 9
Which one of the following is known as the line that connects between the metering
device and the evaporator: - answer Inlet line
Approximately _____ voltage is required for creating a spark on a spark ignition system:
- answer 15,000V
Which one of the following in the refrigeration cycle changes the refrigerant from low
pressure gas to high pressure gas: - answer Compressor
Heat transfer that takes place in liquids and gases in which of the following: - answer
Convection
Which of the following is used to measure the pressure drop across the air filter: -
answer Manometer
What will be typical range of the current sensor: - answer 4-20 mA
, RTD which measure temperature have a positive temperature coefficient: - answer
True
______ temperature is the temperature is the temperature below which moisture
condense out of air - answer Dew Bulb
Curved boundary In Psychrometric chart indicates which of the following: - answer
Dew point temperature line
_____ is a combination of both sensible heat and latent heat: - answer Enthalpy
The heat energy change that is associated with a change in the phase (state) is: -
answer Latent Heat
In water-tube boilers, pressures range from ______ : - answer 50 to 5,000 psig
Which one of the following is used in systems for pressurizing the building: - answer
Exhaust or relief dampers
The temperature-resistance characteristic of a thermistor is _________ : - answer Non
linear
At _________ this superheated refrigerant vapor pressure and temperature is added: -
answer Compressor
For every 1000 feet above sea level,the capacity of a natural gas furnace is de-rated by
_______ - answer 4%
If the surrounding air is colder than the skin temperature, the body gains heat: - answer
False
The power developed by the centrifugal pump is proportional to _________ its speed: -
answer CUBE
Mineral oils are not to be used with HFC alternate refrigerants: - answer True
Flue gas temperatures at which the high-efficiency furnaces operate typically is: -
answer 100 to 275 degrees
Which of the following type of controllers are used in HVAC applications: - answer PI
According to ASME, safety valve of the boiler should be tested for every _____ days: -
answer 30
In Psychrometric ________ indicates which of the following: Dew point temperature line:
- answer Chart curve boundary
questions with correct answers 100%
guaranteed
Which of the following is not the product of incomplete combustion: - answer Oxides of
nitrogen
An oil trap is required at the base of the discharge line of the vertical riser is _____ or
above - answer 8 feet
A diode allows current to flow in one direction: - answer True
1 Watt = _____ Btu - answer 3.41
Current in a closed circuit is limited by which of the following: - answer resistance
An oil separator is located in the _____: - answer Discharge line
______ is the heat that is absorbed or extracted when a substance changes its state: -
answer Latent heat
_______ is the temperature at which oil starts to produce a waxy substance that may
interfere with the refrigeration system: - answer Floc Point
1 kWh of electric power is equivalent to ______ Btu per hour: - answer 3412
What will be the resistance in the circuit if the supply voltage is 30V and current flowing
through the circuit is 5A: - answer 6 OHM
Gas valves operate at _____ voltage: - answer 24V
_______ use two special helical rotors that introduce suction vapors then compress
them: - answer Screw Compressor
,A high pressure steam boiler operates at a pressure greater than ______ : - answer 15
PSIG
In Fire tube boiler, which of the following pass through the tubes: - answer Flue Gas
1 kilo watt = ______ Btu - answer 3140 BTU
Turning the TXV valve stem in _______ direction increases super heat: - answer
Clockwise
Which of the following compressor uses pistons, cylinders and valves to compress the
refrigerant gas: - answer Reciprocating Compressor
Most of the heat transfer from the heat exchanger is by which of the following: - answer
Convection
Relays and contactors are ____ control switches: - answer 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: - answer Daltons Law
At 32°F, 1 lb of ice can be changed to 1 lb of water by adding ____ Btu - answer 144
BTU
Which of the following circuit does not have multiple paths for current flow: - answer
series
Dual voltage three phase motor has _____ number of terminals - answer 9
Which one of the following is known as the line that connects between the metering
device and the evaporator: - answer Inlet line
Approximately _____ voltage is required for creating a spark on a spark ignition system:
- answer 15,000V
Which one of the following in the refrigeration cycle changes the refrigerant from low
pressure gas to high pressure gas: - answer Compressor
Heat transfer that takes place in liquids and gases in which of the following: - answer
Convection
Which of the following is used to measure the pressure drop across the air filter: -
answer Manometer
What will be typical range of the current sensor: - answer 4-20 mA
, RTD which measure temperature have a positive temperature coefficient: - answer
True
______ temperature is the temperature is the temperature below which moisture
condense out of air - answer Dew Bulb
Curved boundary In Psychrometric chart indicates which of the following: - answer
Dew point temperature line
_____ is a combination of both sensible heat and latent heat: - answer Enthalpy
The heat energy change that is associated with a change in the phase (state) is: -
answer Latent Heat
In water-tube boilers, pressures range from ______ : - answer 50 to 5,000 psig
Which one of the following is used in systems for pressurizing the building: - answer
Exhaust or relief dampers
The temperature-resistance characteristic of a thermistor is _________ : - answer Non
linear
At _________ this superheated refrigerant vapor pressure and temperature is added: -
answer Compressor
For every 1000 feet above sea level,the capacity of a natural gas furnace is de-rated by
_______ - answer 4%
If the surrounding air is colder than the skin temperature, the body gains heat: - answer
False
The power developed by the centrifugal pump is proportional to _________ its speed: -
answer CUBE
Mineral oils are not to be used with HFC alternate refrigerants: - answer True
Flue gas temperatures at which the high-efficiency furnaces operate typically is: -
answer 100 to 275 degrees
Which of the following type of controllers are used in HVAC applications: - answer PI
According to ASME, safety valve of the boiler should be tested for every _____ days: -
answer 30
In Psychrometric ________ indicates which of the following: Dew point temperature line:
- answer Chart curve boundary
