NATE AIR CONDITIONING AND HEAT PUMPS FINAL EXAM PREP 2025/2026 ACCURATE QUESTIONS WITH CORRECT DETAILED ANSWERS ||100% GUARANTEED PASS RECENT VERSION

NATE AIR CONDITIONING AND HEAT PUMPS FINAL EXAM PREP 2025/2026 ACCURATE QUESTIONS WITH CORRECT DETAILED ANSWERS ||100% GUARANTEED PASS RECENT VERSION 1. Which of the following should be used to leak-test refrigerant tubing? a. Compressed air b. Dry nitrogen c. Oxygen d. Water - ANSWER b (Dry nitrogen) 2. Of the motors commonly used in HVACR systems, which type has the lowest starting torque? a. PSC motor b. Shaded-pole mole c. Split-phase motor d. Three-phase motor - ANSWER b (Shaded-pole motor) 3. What is the typical phase angle for a split-capacitor motor? a. 15° b. 30° c. 75° d. 90° - ANSWER b (30°) 4. What determines the staging of a two-speed compressor in a heat pump application? a. Deviation from setpoint of the thermostat b. Discharge pressure c. Outdoor ambient d. Suction vapor temperature - ANSWER a (Deviation from setpoint of the thermostat) 5. Which of the following is measured to determine the total resistance to air flow in a ductwork system? a. Current draw of the compressor motor b. External static pressure at the air handler or furnace c. Power input to the electric heater d. Temperature rise across the electric heater - ANSWER b (External static pressure at the air handler or furnace) 6. External static pressure is the sum of the ____ and the ____. a. absolute static pressure entering the air filter, absolute static pressure leaving the air filter b. absolute static pressure entering the indoor blower, absolute static pressure leaving the indoor blower c. absolute supply static pressure, absolute return static pressure d. static pressure entering the evaporator coil, static pressure leaving the evaporator coil 7. See page 172 - ANSWER c (absolute supply static pressure, absolute return static pressure) 8. What is the output of a residential electric furnace when the voltage impressed is equal to 235 V and its current draw is 40 A? a. 10,150 Btuh b. 29,530 Btuh c. 32,080 Btuh d. 42,300 Btuh Btuh = W x 3.413 W = V x A See page 175 - ANSWER c (32,080 Btuh) 9. Use the collected service data below to calculate the air flow volume for a residential electric furnace: Voltage = 240 V ac Current draw = 40 A Entering air temperature = 70°F Leaving air temperature = 105°F a. 798 cfm b. 867 cfm c, 936 cfm d. 1,100 cfm cfm = (voltage x current x 3.413) / (temperature rise x 1.08) - ANSWER b (867 cfm) 10. What is the maximum recommended face velocity for air leaving a supply register? a. 300 ft/min b. 450 ft/min c. 500 ft/min d. 700 ft/min - ANSWER d (700 ft/min) 11. Temperature readings taken on the refrigerant discharge line 6 in. from the compressor must never exceed ____°F. a. 150°F b. 175°F c. 200°F d. 225°F - ANSWER d (225°F) 12. What problem results when the limit temperature of the discharge line at the compressor is exceeded? a. Evaporator superheat will be excessive, causing capacity loss b. Gassing of the indoor metering device will occur during the cooling cycle c. Subcooling in the condenser will decline to a dangerously low level d. Temperature in the compressor will be high enough to vaporize the lubricant - ANSWER d (Temperature in the compressor will be high enough to vaporize the lubricant) 13. The NEC approves a ____ dual-element time-delay fuse as overcurrent protection for a 20-A motor? a. 20-A b. 30-A c. 40-A d. 60-A - ANSWER d (60-A) 14. Voltage supplied to a motor may vary from the rated voltage by ____%. a. +0%, -0% b. +0%, -10% c. +10%, -0% d. +10%, -10% - ANSWER d (+10%, -10%)