Exam (elaborations)
NATE CORE STUDY GUIDE – COMPLETE GUIDE
- Course
- Institution
NATE CORE STUDY GUIDE – COMPLETE GUIDE
[Show more]
Seller
Follow
Studyhall
Reviews received
Content preview
NATE CORE STUDY GUIDE – COMPLETE GUIDEWhich of the following is not the product of incomplete combustion: ✔️Ans
- Oxides of nitrogen
An oil trap is required at the base of the discharge line of the vertical riser is
_____ or above ✔️Ans - 8 feet
A diode allows current to flow in one direction: ✔️Ans - True
1 Watt = _____ Btu ✔️Ans - 3.41
Current in a closed circuit is limited by which of the following: ✔️Ans -
resistance
An oil separator is located in the _____: ✔️Ans - Discharge line
______ is the heat that is absorbed or extracted when a substance changes its
state: ✔️Ans - Latent heat
_______ is the temperature at which oil starts to produce a waxy substance that
may interfere with the refrigeration system: ✔️Ans - Floc Point
1 kWh of electric power is equivalent to ______ Btu per hour: ✔️Ans - 3412
What will be the resistance in the circuit if the supply voltage is 30V and
current flowing through the circuit is 5A: ✔️Ans - 6 OHM
Gas valves operate at _____ voltage: ✔️Ans - 24V
_______ use two special helical rotors that introduce suction vapors then
compress them: ✔️Ans - Screw Compressor
A high pressure steam boiler operates at a pressure greater than ______ :
✔️Ans - 15 PSIG
In Fire tube boiler, which of the following pass through the tubes: ✔️Ans -
Flue Gas
,1 kilo watt = ______ Btu ✔️Ans - 3140 BTU
Turning the TXV valve stem in _______ direction increases super heat: ✔️Ans
- Clockwise
Which of the following compressor uses pistons, cylinders and valves to
compress the refrigerant gas: ✔️Ans - Reciprocating Compressor
Most of the heat transfer from the heat exchanger is by which of the following:
✔️Ans - Convection
Relays and contactors are ____ control switches: ✔️Ans - 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: ✔️Ans -
Daltons Law
At 32°F, 1 lb of ice can be changed to 1 lb of water by adding ____ Btu ✔️Ans
- 144 BTU
Which of the following circuit does not have multiple paths for current flow:
✔️Ans - series
Dual voltage three phase motor has _____ number of terminals ✔️Ans - 9
Which one of the following is known as the line that connects between the
metering device and the evaporator: ✔️Ans - Inlet line
Approximately _____ voltage is required for creating a spark on a spark ignition
system: ✔️Ans - 15,000V
Which one of the following in the refrigeration cycle changes the refrigerant
from low pressure gas to high pressure gas: ✔️Ans - Compressor
Heat transfer that takes place in liquids and gases in which of the following:
✔️Ans - Convection
,Which of the following is used to measure the pressure drop across the air
filter: ✔️Ans - Manometer
What will be typical range of the current sensor: ✔️Ans - 4-20 mA
RTD which measure temperature have a positive temperature coefficient:
✔️Ans - True
______ temperature is the temperature is the temperature below which
moisture condense out of air ✔️Ans - Dew Bulb
Curved boundary In Psychrometric chart indicates which of the following:
✔️Ans - Dew point temperature line
_____ is a combination of both sensible heat and latent heat: ✔️Ans -
Enthalpy
The heat energy change that is associated with a change in the phase (state)
is: ✔️Ans - Latent Heat
In water-tube boilers, pressures range from ______ : ✔️Ans - 50 to 5,000
psig
Which one of the following is used in systems for pressurizing the building:
✔️Ans - Exhaust or relief dampers
The temperature-resistance characteristic of a thermistor is _________ :
✔️Ans - Non linear
At _________ this superheated refrigerant vapor pressure and temperature is
added: ✔️Ans - Compressor
For every 1000 feet above sea level,the capacity of a natural gas furnace is de-
rated by _______ ✔️Ans - 4%
If the surrounding air is colder than the skin temperature, the body gains heat:
✔️Ans - False
, The power developed by the centrifugal pump is proportional to _________ its
speed: ✔️Ans - CUBE
Mineral oils are not to be used with HFC alternate refrigerants: ✔️Ans -
True
Flue gas temperatures at which the high-efficiency furnaces operate typically
is: ✔️Ans - 100 to 275 degrees
Which of the following type of controllers are used in HVAC applications:
✔️Ans - PI
According to ASME, safety valve of the boiler should be tested for every _____
days: ✔️Ans - 30
In Psychrometric ________ indicates which of the following: Dew point
temperature line: ✔️Ans - Chart curve boundary
1 horsepower = _________ watts: ✔️Ans - 746
Dew point temperature is the temperature at which web bulb temperature is
_________ the dry bulb temperature: ✔️Ans - Equal to
The speed of 4 pole motor is about ______ rpm: ✔️Ans - 1800
A suction line accumulator is used for which of the following purpose:
✔️Ans - Prevent liquid refrigerant from entering compressor
Locked Rotor Ampere (LRA) current of a motor will be typically ________ times
the normal running current of the motor: ✔️Ans - 5 to 7 times
Which of the following motor is best suited for speed control applications:
✔️Ans - DC Shunt motors
Square cut or butt joints are not permitted on corners of ductboard sections:
✔️Ans - True
A thermostatic expansion valve modulates to maintain suction _____: ✔️Ans
- Super Heat
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Studyhall. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $22.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83507 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now