NATE CORE question and answers 2023

NATE CORE question and answers 2023When explaining to a customer that you have topped off the system charge, which of the following terms is most appropriate? Refrigerant It is important to be _____ in filling out service orders so that office staff, other technicians, and customers will know what work you completed on the job. All of the above (clear, complete, concise) The ability to utilize all types of communication skills is _____ to the HVACR technician Very important Listening carefully to what a customer is telling you _____. Can help you diagnose the problem When you arrive at a service call and meet the customer, you should ______. Listen to the customer first, than ask questions What is the volume of a room measures 10ft by 20ft with an 8ft ceilings? 1,600 ft3 What is the cfm requirements for an 1,800-ft2 house with 8ft ceilings , if 5 air changes per hour are needed? 1,200 cfm What is the cfm requirement for an 2,400-ft2 house with 8ft ceilings, if five air changes per hour are needed? 1,600 cfm What is the cross-sectional area of a 10 in round metal duct? 79 in2 How fast does air with a velocity pressure of 0.20 in w.g. move through a round duct? 1,800 ft/min How fast does air move with a velocity pressure of 0.20 in w.g. move through a square duct? 1,800 ft/min Customers depend on you to be _______. All of the above (honest, loyal, patient) Before leaving a service call, you should be sure to ______. Demonstrate system operation and describe basic maintenance procedures to the customers What is the advantage of using a tube cutter to cut copper pipe? All of the above (It can cut hard or soft drawn copper, It leaves no metal shavings to contaminate the system, It produces a clean, square cut) Spring-type benders may be used on ______. Soft drawn copper A flaring tool is used to ________. Make a mechanical joint in tubing A swaging tool is used to _______. Solder tubing without the use of couplings What is one of the advantages of a glass-stem thermometer? It is very accurate In discussing human comfort, the temperature most commonly referred to is _______. Dry-bulb A sling psycrometer uses two glass-stem thermometers. One measures dry-bulb, and the other measures ________. Wet-bulb A standard refrigeration manifold uses what type of element to measure pressures? Bourdon tube What is the pressure range of a standard compound gauge on a refrigeration manifold? 30 in. Hg to 350 psig What is the best tool for removing moisture and non-condensibles from a system before adding refrigerant Vacuum pump A vacuum gauge reads pressure in _______. Microns Which of the following is not a method of leak detection? Micronic To prevent the release of refrigerant to the atmosphere while removing it from a system, what type of equipment must be used? Recovery machine An anemometer uses a small fan blade to measure _______. Air velocity What is one of the advantages of using silver brazing rods for copper to copper joints? No flux is required "Housekeeping" includes ________. All of the above (Disposal of waste, fire prevention and protection, proper storage of materials) What type of eye protection should you wear when drilling overhead? Goggles Wat agency regulates cylinders and chemicals transported in a service vehicle? DOT (Department of Transportation) Material safety Data Sheet _________. Contain information about personal protective equipment When should oxygen be used in a refrigeration system? Never What is the maximum safe storage temperature of a refrigerant cylinder filled to 80% capacity by weight? 125 degrees F Which of the following classifications of fire extinguishers should be used for electrical fires? C Which of the following categories could be considered a hazardous atmosphere in a confined space? All of the Above (Asphyxiating, Flammable, Toxic) Which of the following best describes an asphyxiating atmosphere? Low oxygen levels If a ladder is placed against a wall that is 20 ft tall, what is the proper distance away from the wall for the base of the ladder? 5 Ft When using a ladder, you should always _______. maintain three points of contact What is one of the most important safety precautions that you can take when working on electrical equipment? Disconnect and lock out power before starting unless testing requires the power to be on When does a ground fault circuit interrupter open an electric circuit? When current travels through a ground path other than the neutral Proper lockout/tagout procedures state that the locks should be placed on a lockout device may be removed ________. Only by the person who installed the locks A natural cooling process produced by moisture on the skin changing to low-pressure steam is called ________________ Evaporation During the heating season, human comfort can be enhanced without changing the temperature of the air by ______________________ Adding moisture During the cooling season, dampers on bypass humidifiers should be ______________ Completely closed All matter can exist as a ______________ Solid, liquid, gas (all of the above) Stored energy is called _____________ energy Potential Heat that you can feel and measure directly with a thermometer is called ____________ heat Sensible The heat energy change associated with a phase (state) change is called __________ heat Latent The amount of heat (Btu) needed to raise the temperature of 1lb of a substance 1 degree F is called the ______________ heat of the substance Specific The latent heat of fusion is the amount of energy required to change 1lb of a substance from the _________ phase to the _____________ phase without changing its remperature Liquid, solid At 32 degrees F, 1 lb of ice can be changed to 1lb of water by adding ________________ Btu 144 Btu At 212 degrees F, 1lb of water can be changed to 1lb of steam by adding _________ Btu 970 Btu When liquid and vapor phases of a substance exist together, and no more liquid can vaporize without more energy being added, the vapor is said to be _______________ Saturated When a vapor is heated to a temperature higher than its saturation point, both the added heat and the temperature above saturation are called _______________ Superheat The process of molecules escaping from the surface of a liquid is called Evaporation