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HVAC EXCELLENCE - ELECTRICITY EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026
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Current flow is: - correct answer-The flow of electrons in the circuit. Impedance is: - correct answer-Opposition to alternating current flow. Like charges; - correct answer-repel each other. Any material that will readily release electrons is called; - correct answer-A conductor The symbol for current is; - correct answer-I
Which of the following materials would be best suited for use as a semi-conductor? - correct answer-silicon The safety ground conductor is usually color coded; - correct answer-green or bare. An electron has; - correct answer-a negative charge. Resistance is: - correct answer-Opposition to current flow. How many watts of power are used by a heater operating at 240 volts and drawing 5 amps? - correct answer-1200 watts Which of the following meters must use its internal power to check a load or circuit? - correct answer-Ohmmeter In electrical wiring, a black colored wire in an alternating current circuit usually indicates; - correct answer-the hot conductor.
When testing a capacitor with an analog or digital ohmmeter, the meter should; - correct answer-measure low resistance then return to high reading. What is the term used to describe the output side of a transformer? - correct answer-Secondary side. One horsepower is equal to __________ watts. - correct answer- 746 How much resistance must be placed in a 120 volt circuit in order to limit the current to 2 amps? - correct answer-60 Ohms A parallel circuit contains a 18 ohm and a 9 ohm resistor. The total resistance equals; - correct answer-6 ohms. In a series circuit, the voltage drop across each resistance (load) will. - correct answer-add up to equal the source voltage.
The total resistance of a parallel circuit will be; - correct answer- less than the smallest resistance. Which of the following statements about current is true? - correct answer-Current flow will increase when voltage increases. When resistors are wired in parallel; - correct answer-the voltage drop across each resistor will be the same as the applied source Which of the following is equal to 2.1KW? - correct answer-2, Watts Which of the following is equal to 100 milliamps? - correct answer-0.10 amperes A capacitor analyzer is designed to read; - correct answer-the capacitive resistance of a capacitor.
An electronically commutated motor (ECM) is designed to; - correct answer-provide proper air flow under various conditions. Resistance can be calculated by: - correct answer-E divided by I. Divided Voltage can be calculated by; - correct answer-I times R An ohmmeter should never be connected to; - correct answer-a live circuit or a charged capacitor until it has been discharged Which of the following would be considered an inductive load? - correct answer-electric motor The voltage to ground of a "high Leg" or "Stinger Leg" on a three phase open Delta system will be approximately; - correct answer- 208
A transformer has 1000 turns of wire in the primary coil and 500 turns in the secondary coil. If 120 volts are applied, the output voltage will be. - correct answer-60 volts A transformer has 1000 turns of wire in the primary coil and 2000 turns in the secondary coil. If 120 volts are applied, the output voltage will be; - correct answer-240 volts Which of the following is the symbol for Impedance in an AC circuit? - correct answer-Z When current flows in a two wire circuit (such as 120 volts) if a clamp on amp meter is clamped around both wires. What measurement would you expect? - correct answer-Zero amps due to cancelation of the two fields. If the conductor in an AÇ circuit is wound into a coil, the resulting EMF opposes the supply voltage. This opposition is called. - correct answer-inductive reactance.
Capacitors are always connected _____________ to the start winding. - correct answer-in series Which meter is used to bench check a motor for shorts or open windings? - correct answer-ohmmeter. A solenoid valve coil operates on the principle of - correct answer- electromagnetism. When checking the windings of a three phase motor; - correct answer-all three terminals should show the same resistance. When testing the windings of a single phase motor, - correct answer-the common to run terminals show the lowest resistance. Direct Digital Control (DDC) is - correct answer-electronic controls use for equipment operation and monitoring
A step up transformer increases; - correct answer-voltage. Transformers are rated according to; - correct answer-VA at the secondary. Utility companies usually supply residential homes with ______________ service. - correct answer-240V, single phase, three wire What connects to the terminals T1, T2, & T3 on a contactor or motor starter? - correct answer-Load connections Circuit breakers & fuses are primarily used to provide; - correct answer-protection from an overload of current. Excessive current can be caused by; - correct answer-short circuit.
The ______________ drawing illustrates where the components are located in small appliances. - correct answer-pictorial Which of the following motors is most energy efficient. - correct answer-ЕСM On a good single-phase compressor motor, which winding terminals have the highest resistance? - correct answer-run to start. 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, and Common to ground 20.4; This indicates a/an; - correct answer-grounded condition. With a motor running at full load, voltmeter leads are placed on L and T1 terminals of the contactor. The voltmeter indicates no measurable voltage. This is an indication of. - correct answer- good clean contacts.
When the temperature of a negative temperature coefficient (NTC) thermistor increases, its resistance will. - correct answer- decrease. When the temperature of a positive temperature coefficient (PTC) thermistor increases, its resistance wilI; - correct answer-increase. A transducer can create a signal based on. - correct answer- pressure. A typical thermocouple used on a gas furnace can. - correct answer-generate a small DC electrical current. To discharge a capacitor prior to ohmmeter testing. - correct answer-use a 20,000 ohm, 2 to 5 watt resistor across the terminals. Which of the following is an acceptable temporary replacement for a run capacitor rated at 35MFD @ 440VAC - correct answer- 37.5MFD @ 440VAC.
In the schematic, what voltage would be found across the transformer primary? - correct answer-240 volts. In the schematic, what voltage would be found across the fuse in line #10 with the thermostat closed? - correct answer-0 volts. In the schematic, what voltage would be found from terminal G to the load side of the transformer? - correct answer-0 volts In the schematic, what voltage would be found across the contacts when energized in line #8 - correct answer-0 volts. In the schematic, what voltage would be found from terminal Y to the input side of the coil on line #11? - correct answer-0 volts. In the schematic, what voltage would be found from terminal Y to the output side of the coil on line #11? - correct answer-0 volts
When troubleshooting the A/C system in the schematic, the following conditions are found. The thermostat contacts are closed. The compressor and condenser fan motors are short cycling. The blower motor is not running. This could be caused by. - correct answer-a faulty blower motor or blower relay. When troubleshooting the A/C system in the schematic, the following conditions are found. The thermostat contacts are closed. The compressor and condenser fan are not running. The blower motor is running. This could be caused by. - correct answer-the HP, LP, overloads, or oil pressure switch are open (line #11). When troubleshooting the A/C system in the schematic, the following conditions are found. The thermostat contacts are closed. The compressor and condenser fan motors are short cycling. The blower motor is not running. When the fan switch at the thermostat is moved from the AUTO position to the FAN ON position, the blower runs. This could be caused by. - correct answer-a faulty thermostat - AUTO / FAN ON switch. In the schematic, the crankcase heater will operate; - correct answer-when the compressor is off.
Two 120 volt incandescent light bulbs are wired in series, one is a 60 watt bulb, the other is a 4 watt bulb. The result would be - correct answer-both bulbs light A 240 Volt, 3 wire circuit can be split into two 120 Volt circuits. - correct answer-TRUE Which of the following in not a factor in determining impedance in an AC circuit? - correct answer-Frequency When current flows, a _______________ is produced around the conductor. - correct answer-magnetic field Technician #1 says that an open transformer coil is indicated by a reading of infinity on an analog ohmmeter. Technician #2 says that a shorted transformer coil is indicated by a reading of infinity on an analog ohmmeter.
Which technician is correct, or are both technicians correct? - correct answer-Technician #2 only The terminals T1, T2, & T3 are located at the _______ of a contactor. - correct answer-top Circuit fuses and breakers are primarily used to protect - correct answer-loads
