HVAC Certification Practice Tests Questions With 100% Correct Answers.

Propane and Butane are _______ than air: - Heavier What will be the resistance in the circuit if the supply voltage is 30V and current flowing through the circuit is 5A - 6 ohms Temperature at which oil starts to produce a waxy substance that may interfere with the refrigeration system - Floc point What manifold gauge set is used to charge, evacuate, add oil and recover refrigerant from a refrigeration and air conditioning system? - Yellow hose Where is the oil separator located? - Discharge line Higher the ambient temperatures, ____ will be the evacuation time of the refrigerants from the system - Lesser 1 Watt is equal to - 3.41 Btu's Heat that is absorbed or extracted when a substance changes its state is - Latent heat Where is the sight glass present in the refrigeration cycle? - Liquid line Which shall not be used near flammable materials? - Halide leak detector Current in a closed circuit is limited by: - ResistanceWhen there is an increase in the heat load on the evaporator, the refrigerant will tend to evaporate at a _____ rate - Faster At what voltage is gas valve operates? - 24V Furnaces are placed into categories based upon - Venting characteristics What type of compressor uses two special helical rotors that introduce suction vapors then compress them? - Screw compressors 1 kWh of electric power is equivalent to how many Btu per hour: - 3412 A high pressure steam boiler operates at a pressure greater than - 15 psig