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39 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Inductance is produced when _____________________ passes through a coil, creating a magnetic field around the conductor, which then creates _____________________, which opposes the _____________ it creates. |
- Alternating Current - Counter voltage (Back EMF) - Voltage |
Transformers and motor windings are examples of inductive circuits. |
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In a parallel circuit, voltage ____________ but current __________ depending on the ______________ of each load. |
- constant - changes - resistance |
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How does a Capacitor increase the efficiency of an AC circuit in a motor? |
Capacitance causes the current and voltage to go out of phase with each other. |
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What type of current is used in batteries and why? |
Direct Current - because it is constant and only travels in one direction |
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The watt is a unit of _________________, and is equal to ___________ _______. |
- Electrical power - 3.41 BTUs |
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Horsepower is a unit of ___________________, and is equal to ______________ or _______________. |
Mechanical power - 550 ft pounds - 750 watts |
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True or False? Ammeters are read in series with the load. |
True |
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True or False? Voltmeters are read in series with the load. |
False (parallel) |
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True or false? Ohmmeters are read in series with the load. |
False They are read across the device or circuit (device must be isolated or circuit must be unpowered for safety) |
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There are 4 types of controls in a typical circuit. Name them. |
Manual Automatic Operating (normally open) Safety (normally closed) |
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What is a load? |
A power consuming device that changes electrical current into mechanical energy (gas valve, motor), or electrical energy (transformer) |
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True or false? Resistors in series are always greater than the total resistance of a circuit. |
False |
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True or false? Resistors in parallel are always less in value than the total resistance of a circuit. |
False |
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True or false? Capacitors in a series always have a smaller value than the total resistance. |
False |
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True or false? The neutron is the uncharged core of an atom. |
False The neutron is the uncharged portion of the nucleus. |
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True or false? The nucleus is the core of the atom. |
True |
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Which direction does electrical current flow? |
Neg to pos |
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What is static electricity? |
Transfer of electrical charge thru friction. |
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What is electrostatic energy? |
It is the positive or negative force exerted by matter containing static electricity. |
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Semi conductors use the principle of ___________________ to transfer negative charge (electrons). |
Hole flow |
Remember conductors do not have tightly bound electrons |
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The volt is the unit of ___________ ______________. It’s symbol is ___. |
Electromotive force. (E) |
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Amperage is the unit of ___________ _____________, and it’s symbol is ____. |
Electric current. (I) |
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The ohm is the unit of ___________ ___________. It’s symbol is __. |
Electric resistance. (R) |
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One amp is the amount of current that will... |
move through one ohm of resistance when one volt of force is applied. |
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One volt is the amount of force required to ... |
move one Amp of current through one Ohm of resistance. |
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One Ohm is the amount of resistance that will... |
allow one volt to move one amp of current. |
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True or false? In a series circuit, the resistance can vary according to the resistance of each load, but the voltage remains constant. |
False Voltage can vary depending on the resistance of each load, but current is constant. |
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True or false? In a parallel circuit, total resistance is always less than the resistance of each load. |
True |
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The most common frequency of a DC device is ______. |
0 No frequency in Direct Current! |
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The most common frequency in an AC device is ____. |
60 Hz |
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Frequency refers to the amount of ____________ the voltage undergoes in ____ ___________. |
Cycles One second |
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Transformers rely on _____________. |
Inductance |
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Inductance is the ______________________ created when AC passes through a conductor. |
Magnetic field |
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Capacitors rely on ____________ to improve efficiency of a circuit. |
Capacitance |
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How does one find amount of volt force (E) in an equation? |
(R) ohms x (I) Amperage |
Pyramid |
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How does one find Volt force (E) in an equation when presented with watts and amperage? |
E = W/I |
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What are the most relevant units used with capacitance? |
Volts and microfarads |
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What are the amperage ratings for the following gauges of wire? 10 12 14 |
#10 = 30 amp #12 = 20 amp #14 = 15 amp |
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The two most important ratings of a capacitor are: |
Volts and microfarads |
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