Principles of Electrical and Refrigeration Theory 1. What is the symbol for impedance? a. R b. I c. Z d. P
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2. The safety ground conductor for A/C circuit is usually color coded _________. a. red b. green c. black d. white
Air Conditioning 3. Heat which causes a change in temperature of a substance is called: a. latent heat. b. sensible heat. c. superheat. d. regular heat.
4. What is heat, which causes a change in the state of a material without a change in temperature, called? a. Latent heat b. Sensible heat c. Superheat d. Regular heat
Commercial Air Conditioning 5. What is a sling psychrometer used to measure? a. Latent heat b. Super heat c. Wet and dry bulb temperature d. Barometric pressure
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6. A compressor is operating with a discharge pressure of 235.3 psig and a suction pressure of 35.3 psig. What is the compression ratio (pumping ratio)? a. 10:1 b. 8:1 c. 7:1 d. 5:1
Commercial Refrigeration 7. In a (direct expansion) evaporator, liquid refrigerant must boil away as close to the end of the coil as possible in order to: a. ensure proper oil return. b. ensure that frost does not accumulate. c. sub-cool the compressor. d. operate at high efficiency.
8. An thermal expansion valve that is stuck wide open will cause ___________. a. low suction pressure b. a flooded evaporator c. excessive superheat d. a starved evaporator
Heat Pump Service 9. What is the major difference between a heat pump and an air conditioner? a. Condenser b. Thermostatic expansion valve c. Evaporator d. Reversing valve
10. What device controls the supplementary electric heat according to the outdoor temperature? a. Auxiliary temperature control b. Outdoor auxiliary thermostat c. Outdoor ambient thermostat d. Indoor thermostat only
Heat Pump Installation 11. Which of the following is not a factor that should be considered when installing an outdoor unit? a. Return air b. Wind factors c. Sound transmission d. Snow fall
12. What is the minimum clearance for access panels on an outdoor condensing unit? a. 36 inches b. 30 inches c. 15 inches d. 10 inches
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Gas, Oil and Combustion 13. One BTU is the amount of heat required to raise the temperature of: a. one pound of ice one-degree Fahrenheit. b. one pound of water one-degree Fahrenheit. c. one gallon of water one-degree Fahrenheit. d. one gallon of water eight degrees Fahrenheit.
14. What is the primary composition of natural gas? a. 65 percent methane b. 75 percent methane c. 85 percent methane d. 95 percent methane
Electric Heat 15. The electric heat element is usually made of what material? a. Copper with a brass coating b. Nickel with a cadmium coating c. Nickel and steel d. Nickel and chromium
16. Which of the following is an example of a resistive load? a. Bimetal switch b. Crankcase heater c. Transformer d. Motor
Residential Heat Load Calculation 17. An oversized heating and cooling system can cause which of the following? a. Operating cost and relative humidity in the structure will decrease significantly. b. Moisture damage to a furnace heat exchanger and inadequate humidity removal during cooling cycles. c. The structure will develop low humidity levels in the cooling season and high humidity in the winter. d. Equipment will last longer and require less energy to operate due to the shorter run time.
18. When the temperatures of a structure both inside and outside are equal, there is _____. a. no heat transfer b. latent heat transfer to the outside c. thermal heat transfer of sensible heat d. a lower rate of relative humidity
Low-GWP Refrigerant Safety and Training 19. Polyolester (POE) oils stored in plastic containers will _______. a. separate b. become more alkaline c. become acidic d. absorb moisture through the plastic
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20. R-407C has _______-. a. a foul odor b. to be charged in the vapor phase c. the ability to fractionate d. no temperature glide
Green Awareness 21. What is a carbon footprint? a. The carbon deposits from burning gasoline. b. The amount of carbon dioxide that is produced to support your lifestyle. c. The amount of carbon in the atmosphere produced by the world's lifestyle. d. The amount of carbon in the stratosphere.
22. What is energy management? a. A rule that the total amount of energy stays constant in an isolated system over time. b. Recovering energy lost while using mechanical equipment. c. Reading the electric and fuel gas meters every month. d. The monitoring and controlling of energy consuming devices.