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23 Cards in this Set
- Front
- Back
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What is the symbol for impedance? |
Z |
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The safety ground conductor for A/C circuit is usually color coded |
Green |
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Resistance is __________ |
Opposition to current flow |
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How many watts of power are used by a heater operating at 480 volts and drawing 5 amps? |
2400 watts |
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What type of meter uses its own power source? |
Ohmmeter |
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Fuses are sized by: |
Volts and Amps |
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Two 120 volt A/C incandescent light bulbs are wired in series; one is a 60 watt bulb and the other is a 4 watt bulb. The result would be _________. |
only the 4 watt bulb will light |
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What would the capacitance be if two Capacitors are wired in parallel, one having 25 mfd rating and the other having 5 mfd rating? |
30 mfd |
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What is the term used to describe the input side of a transformer? |
Primary side |
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How much resistance must be placed in a 240 volt circuit in order to limit the power to 480 watts? |
120 ohmms |
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The total resistance of a parallel circuit will be _______ |
less than the smallest resistance |
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A parallel circuit consists of three resistors:
R1 = 24 ohms R2 = 60 ohms R3 = 40 ohms
What is the total resistance of the circuit? |
12 ohms |
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An electronically commutated motor (ECM) is designed to ________. |
provide proper air flow under various conditions |
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An ohmmeter should never be connected to ___________. |
A live circuit |
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A transformer has 1200 turns of wire in the primary coil and 120 turns in the secondary coil. What will the output voltage be if 240 volts are applied? |
24 volts |
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When current flows, a _____________ is produced around the conductor |
A magnetic field |
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If the conductor in an AC circuit is wound into a coil, the resulting EMF opposes the supply voltage. What is this opposition called? |
Inductive reactance |
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A ___________ is commonly used on a single phase fractional horse power compressor motor to disconnect the start winding after the motor starts. |
Current relay |
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Single phase motor speed is determined by the __________. |
Number of stator poles |
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To change direction of rotation of a three-phase motor _____________. |
reverse the position of any two supply wires |
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A device with built in overload protection used to control a motor is a ___________. |
across the line starter |
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Contactors are rated according to the maximum amperage through the ___________. |
Contacts |
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The ___________ drawing illustrates where the components are located in small appliances |
Pictorial |
