HVAC Electricity Exam Questions and Answers Latest 2024/2025 (GRADED A+)

HVAC Electricity Exam Questions and Answers Latest 2024/2025 (GRADED A+) how much resistance must be placed in 120V curcuit in order to limit the current to 2Amps - ANSWER 60 Ohms when current flows in a 2 wire circuit such as 120v, if a clamp on amp meter is clamped around both wires what measurment would you expect. - ANSWER 0 amps - due to cancellation of 2 fields Current flow is? - ANSWER The flow of electrons in the circuit. What is the symbol for impedence in an AC CIrcuit. - ANSWER Z Impedence is? - ANSWER Oppostion to Alternating current flow. If contacts become badly pitted, it is acceptable to? - ANSWER Replace the contacts or control. Relays are generally used to control inductive loads up to? - ANSWER 10 Amps When resistors are wired in parallel: - ANSWER The voltage drop across each resistor will be the same as the applied source voltage. Contactors are rated according to the maximum amperage through the? - ANSWER Contacts. The ________ Drawing illustrates where the components are located in small appliances - ANSWER Pictorial When the Positive Temp coeffiecent thermistor increases, its resistance will - ANSWER Increase Which meter is used to bench check a motor for shorts or open windings? - ANSWER Ohmmeter Capacitor start capacitor run motor provides - ANSWER Eating running and high starting torque When testing a motor with an ohmmeter, the following measurements are recorded: common to run 4 ohms, common to start 6.2 ohms, run to start 10.2 ohms. Common to ground 20.4; this indicates a - ANSWER A grounded condition Which of the following is an acceptable temporary replacement for a run capacitor HVACElectricity – Exam Questions and Answers Latest 2024/2025 (GRADED) rated at 35 MFD at 440 VAC - ANSWER 37.5 MFD at 440 VAC With a motor running at full load, voltmeter leads are placed on l1 and T12 terminals of the contactor. The voltmeter indicates no measurable voltage. This is an indication of - ANSWER Good clean contacts How to discharge a capacitor prior to ohm meter testing - ANSWER Use a 15000 or 20000 ohm, 225 watt resistor across the terminals A __________ is commonly used on a single phase fractional horsepower capacitor motor to disconnect the start winding after the motor starts - ANSWER Current relay Utility companies usually supply residential homes with________ service - ANSWER 240v, 3-phase, 3-wire If the conductor in a AC circuit is wound into a coil, the resulting EMF opposes the supply voltage. This opposition is called - ANSWER Inductive reactance What connects to the terminal t1, t2, and t3 on a contactor or motor starter? - ANSWER Load connections A solenoid valve operates on the principle of - ANSWER Electromagnetism Circuit breakers and fuses are primarily used to provide - ANSWER Protection from an overload of current To change direction of rotation of a 3-phase motor - ANSWER You must change the position of any two supply wires Which of the following motors is most energy efficient - ANSWER ECM Which of the following is equal to 2.1 KW - ANSWER 2100 Watts Which of the following statements about current is true - ANSWER Current flow will decrease when voltage increases Capacitors are rated in - ANSWER Microfarads and volts The total resistance of a parallel circuit will be - ANSWER Less than the smallest resistance A parallel circuit consists of three resistors. R1 equals 30 ohms, are two is equal to 15 ohms, are 3 is equal to 10 ohms. If the current through r2 is 4 amperes, what is the source voltage - ANSWER 60 volts Which of the following meters must use its internal power to check a load or circuit - ANSWER Ohm meter Which of the following is the correct formula for determining wattage in a electrical circuit - ANSWER W=E times I In electrical wiring, a black colored wire in an alternating current circuit usually indicates - ANSWER The hot conductor A 3-phase load requires a minimum of - ANSWER 3 supply lines The electric meter on a house measures the______passing through it - ANSWER Amperage Fuses are sized by - ANSWER Volts and amps I'm in electrical oil safety switch, what changes the pressure signal to electrical signal - ANSWER Transducer Voltage to a ground of a high leg or stinger leg on a three-phase open Delta system will be approximately - ANSWER 120