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38 Cards in this Set
- Front
- Back
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What is the function of a capacitor? |
To store electricity |
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What is the unit of measure for capacitance? |
Farad |
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What is the unit of measure for frequency? |
Hertz |
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What is Inductance? |
Induced voltage which is opposite in direction to the applied voltage and opposes in change in a AC |
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What is Impedance? |
Total opposition for AC to flow by the combined effect of resistance, inductive reactance and capacitive reactance in an AC circuit |
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What causes opposition to the flow of current in an AC circuit? |
Inductive and capacitance reactance |
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What is the measurment of impedence? |
OHMS |
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What are two things that happen when current flows through a conductor? |
A magnetic field is generated and the conductor heats up |
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What is the common name for the lines of force that make up a field surrounding a magnet? |
Magnetic flux lines |
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What are Four factors that affect resistance of an electrical conductor? |
The wire gauge, length, temperature and material |
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Measurment of power in a DC circuit? |
The watt (I X E=power) |
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In a DC Circuit, what occurs when the voltage is increased while resistance remains constant? |
The Current also increases |
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3 types of DC Electrical Circuits |
Series, parallel and Complex circuits |
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What is electromagnetic induction? |
Transfer of electrical energy by a magnetic field from one conductor to another |
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What should be the correct level in a electrolyte serviced battery? |
3/8 above the plates or up to the hole if it has baffle plates |
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What are paralleling generators and how is the load distributed? |
When two or more generators distribute power at the same time to a load that must be shared equally |
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What is the result of an imbalanced cell in a nickel cadmium battery? |
The current will increase across the cell causing it to heat up |
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What is the most important law applicable to the study of electricity? |
Ohm's Law (E= I x R). |
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What are elements of Ohm's Law? |
Voltage (E), Current (I), and Resisitance (R) |
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What are four sources of eletrical energy? |
Thermal, Light, Pressure, and chemical. |
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What does an electrical circuit consist of? |
1. Source (battery). 2. Resistance- Load (light bulb). 3. Conductors (Wires). |
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What represents capacitance in an AC circuit? |
A capacitor (same as condenser) |
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What is the basic component that only allows current to flow in one direction? |
A diode (acts like a check valve). |
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What is an example of an inductor in a magneto? |
The coil. |
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What is the general purpose of a resistor? |
To limit current. |
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How may the value of a small, fixed resistor be determined? |
By the color of bands on the resistor. |
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What is the concept that describes the relationship between electricity and magnetism? |
Electromagnetism. |
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What is a kilowatt? |
1000's watts. |
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A 24 volt lead-acid battery has how many cells? |
12 cells. Each cell is rated 2 volts |
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What are the units that battery capacity are measured in? |
Amp-hours |
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What should be the specific gravity of the electrolyte in a fully charged lead acid battery? |
It should be between 1.275 and 1.300. |
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What instrument is used to determine the specific gravity of electrolyte in a lead acid battery? |
A hydrometer. |
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Why can a hydrometer not be used to determine the charge of a nickel-cadmium battery? |
The specific gravity of the electrolyte in a nickel-cadmium battery does not change appreciably during charge or discharge of the battery. |
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When using a hydrometer to check the charge of a lead-acid battery, at what temperatures must a correction factor be applied to the reading? |
Adjustments must be made if the temperature of the electrolyte is above 90°F or below 70°F. |
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How are battery compartments protected against corrosion? |
They are coated with special corrosion resistant paint such as bituminous paint. |
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Describe a no-trip circuit breaker (trip free). |
It pops when the circuit gets hot and can't be reset until it has cooled off. |
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Can you store Ni-cad and Lead-acid batteries together? |
No, the fumes from the Lead-acid battery can contaminate the electrolyte in the Ni-cad battery. |
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What happens to the specific gravity of the electrolyte in a lead-acid battery when the temperature changes? |
The specific gravity will vary with temperature variations. If the temperature rises, so will the specific gravity, and the colder it gets you will have lower specific gravity readings. |
