Electricity HVAC Test Questions with Correct Answers

how much resistance must be placed in 120V curcuit in order to limit the current to 2Amps - 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. - 0 amps - due to cancellation of 2 fields Current flow is? - The flow of electrons in the circuit. What is the symbol for impedence in an AC CIrcuit. - Z Impedence is? - Oppostion to Alternating current flow. If contacts become badly pitted, it is acceptable to? - Replace the contacts or control. Relays are generally used to control inductive loads up to? - 10 Amps When resistors are wired in parallel: - 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? - Contacts. The ________ Drawing illustrates where the components are located in small appliances - Pictorial When the Positive Temp coeffiecent thermistor increases, its resistance will - Increase Which meter is used to bench check a motor for shorts or open windings? - Ohmmeter Capacitor start capacitor run motor provides - 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 - A grounded condition Which of the following is an acceptable temporary replacement for a run capacitor rated at 35 MFD at 440 VAC - 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 - Good clean contacts How to discharge a capacitor prior to ohm meter testing - Use a 15000 or 20000 ohm, 225 watt resistor across the terminals