Air Conditioning Certification Exam (Exam Code A-02) Questions With Accurate Answers.

Air Conditioning Certification Exam (Exam Code A-02) Questions With Accurate Answers. Heat which causes a change in temperature of a substance is called; - answersensible heat. Heat which causes a change in state of a material without a change in temperature is called; - answerlatent heat. Heat which is added to a vapor after the change of state occurs is called; - answersuperheat. Heat can travel by; - answerconduction, convection, radiation. The movement of heat by way of fluid (or air) is called; - answerconvection . The movement of heat by direct contact is called; - answerconduction . The standard unit for measuring the quantity of heat in a substance is; - answerthe British Thermal Unit (Btu). A refrigerat gives up heat when; - answerit condenses. It is desirable for refrigerant in the suction line to be slightly superheated in order to; - answerinsure liquid refrigerant does not enter the compressor. The state of refrigerant in the suction line should be; - answerlow pressure/ low temperature. The state of the refrigerant entering the condenser is; - answerhigh pressure/ highly superheated liquid. The evaporator; - answerTransfers heat from the refrigerant to the ambient air. Which of the following is NOT a thermodynamic property of refrigerants? a) Critical point. b) Saturation point. c) Enthalpy. d) Flammability. - answerd) Flammability. The sequential order of steps in the vapor - compression process are; - answercompression, condensation, expansion, vaporization. If a 30 pound cylinder of reclaimed R-12 refrigerant has been stored over night at 70°F, the pressure in the cylinder should be approximately; - answer70.2 Psig. Pressures lower than atmospheric are measured in; a) inches of mercury b) microns c) Psig d) either "A" or "B". - answerd) either "A" or "B". Zero psia (pounds per square inch absolute) is; - answera pressure which cannot be further reduced. Zero psig (pounds per square inch guage) is; - answerthe same as atmospheric pressure. The temperature at which moisture will start to condense from the air is called; - answerdew point temperature. A compound pressure guage measures; - answerpressure and vacuum. A mechanical shaft seal is necessary on a; - answeropen drive compressor. Liquid slugging is; - answerliquid refrigerant in the compressor clearance space. The clearance space in a reciprocating compressor; - answerhas an effect on compressor capacity. Which of the following will cause a change in compressor capacity? a) suction pressure. b) discharge pressure. c) refrigerant vapor density. d) all of the above. - answerd) all of the above The main function of the condenser is to; - answerremove heat from the refrigerant. Refrigerant R12 vapor enters the condenser at 116.9 psig, 100 F. It leaves the condenser at 80 F. Its pressure will be approximately; - answer84.1 psig. There are three basic types of condensers, the air cooled, the water cooled and the __________cooled. - answerevaporative.