HVAC CONTRACTOR EXAM Questions and Answers Latest Verified

HVAC CONTRACTOR EXAM Questions and Answers Latest Verified An instrument that measures potential differences between 2 points in an electrical circuit is called? A. potentiometer B. thermistor C. ohmeter D. voltmeter - CORRECT ANSWER-voltmeter This device uses a thermal sensing bulb at the outlet of the evaporator to sense temperature and control superheat A. automatic expansion valve B. thermostatic expansion valve C. low side float D. schraeder valve - CORRECT ANSWER-thermostatic expansion valve when installing a reversing valve on a heat pump, how many brazed joints should be made? a. 3 b. 5 c. 4 d. 2 - CORRECT ANSWER-4 what would not be considered a misuse of a contractors license? a. advertising under mulitple names b. employing service technicians to work under their license c. loaning license to more than one company d. continue to work on an expired license - CORRECT ANSWER-employing service technicians to work under their license what is used to prevent microbiological growth and help "dirty socky syndrome? a. radiation b. ultraviolet light c. electrostatic filters d. heat rated static filters - CORRECT ANSWER-ultraviolet light a precisely sized drilled hole through which gas flows from the manifold to the burner is known as what a. spud b. drill size c. orifice d. dimple - CORRECT ANSWER-orifice rooftop package hvac units utilize economizers for what primary purpose? a. to exhaust extra indoor air b. to equalize indoor/outdoor pressures c. to allow outside air to be used for cooling in mild weather d. to raise indoor relative humidity - CORRECT ANSWER-to allow outside air to be used for cooling in mild weather what is the minimum gauge required for a 12" galvanized steel connector used to connect a lows heat appliance? a. .019 b. .029 c. .034 d. .2 - CORRECT ANSWER-.029 after cutting pipes they must be reamed for what purpose? a. to clean pipe threads b. to smooth the end of the pipe c. to remove burrs and chips from the inside d. to help the threading process - CORRECT ANSWER-to remove burrs and chips from the inside in manual d what is the suggested friction (IWC) loss for hand dampers? a. .01 b. .08 c. .1 d. .03 - CORRECT ANSWER-.03 a system with a 120 degree saturation temperature in the condenser with R-22 has a liquid line temperature of 105 degrees. what does the temperature difference of 15 degrees represent? a. superheat b. wet bulb c. subcooling d. air temperature difference - CORRECT ANSWER-subcooling when a technician uses a nitrogen cylinder to pressurize a system for leak detection what should be used for safety a. hand valve b. impervious gloves c. pressure regulator d. temperature gauge - CORRECT ANSWER-pressure regulator when the azeotropic blend of refrigerant condenses or evaporates at a different temperature, it is called? a. fractionation b. segregation c. purification d. latent heat of fusion - CORRECT ANSWER-fractionation before brazing copper tubing what should be circulated through the tubing first a. CO b. refrigerant c. oil d nitrogen - CORRECT ANSWER-nitrogen a service technician should adjust the superheat setting on a TXV how often a. never b. when absolutely necessary c. once a month d. routinely - CORRECT ANSWER-when absolutely necessary refer to house 1drawing. calculate the net summer heat gain through the east exterior wall of bedroom 1. select the closest answe