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29 Cards in this Set
- Front
- Back
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One Kilowatt is equal to how many watts?
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1,000 watts.
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What law describes the most fundamental or basic relationships in an electrical circuit?
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Ohm's Law
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What are the three elements of ohm's Law?
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Voltage, Current , and resistance.
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How would you write ohm's law as an equation?
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E= I*R, R=E/I, I=E/R
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If the resistance in a DC circuit remains the same but the voltage doubles, what happens to the amount of current flowing in the circuit?
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It also doubles
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In DC circuit, what unit measures Power?
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Watts
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What three elements are required to form an electrical circuit?
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A source of electrical energy , a load or resistance to use the electricity , and wires or conductors to connect the source to the load.
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Dc Circuit can take of three forms or types. What are they?
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Series, parallel, and complex.
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A 24-volt lead-acid battery has how many cells?
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Twelve.
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A fully charged lead- acid battery has a specific gravity that varies between what two values?
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1.275 and 1.300.
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You must apply a correction to the specific gravity reading of the electrolyte of a load-acid battery when the temperature is outside of what two values?
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Whenever the temperature is less than 70 degrees Fahrenheit or more than than 90 degrees Fahrenheit.
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What is the reason for having separate facilities for storing and servicing nickel-cadmium and lead-acid batteries?
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The electrolytes are chemically opposite and the fumes from one can contaminate the electrolyte of the other.
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The state of charge of a nickel-cadmium battery cannot be determined by measuring the specific gravity of the electrolyte for what reason?
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There is no significant change in the specific gravity of the electrolyte as the battery is charged or discharged in Ni-Cad batteries.
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What is the principal advantage of AC over DC?
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Power can be transmitted over long distances more efficiently and with smaller wires because the voltage can be easily increased or decreased by a transformer.
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What are the three causes of opposition to current flow in an AC circuit?
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Resistance, Inductive reactance, and Capacitive reactance.
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Define Inductance
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An induced voltage which is opposite the direction of the applied voltage.
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What component creates capacitance in AC circuits?
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A Capacitor.
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How does a capacitor store electricity?
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Energy is stored in the form of an electrostatic charge or field that exists between two conductors separated by an insulator.
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What property of an AC circuit is defined by the term impedance?
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Total opposition to current flow.
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What are two reasons that might cause a nickel-cadmium battery to fail to deliver its rated capacity?
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Faulty cells or cell imbalance.
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What electrical values are measured by a typical multimeter ?
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Voltage, Current, Resistance.
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What are the sources of electrical power?
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Mechanical (generator), chemical (battery), photoelectric (light), and thermal heat.
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What instrument is used to determine the specific gravity of electrolyte in a lead acid battery?
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A hydrometer.
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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 temperature of the electrolyte is above 90º F. or below 70º F.
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What is electromagnetic induction?
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It is the transfer of electrical energy by means of a magnetic field. This is the principle of
transformer operation. |
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How are battery compartments protected against corrosion?
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They are coated with special corrosion resistant paint such as bituminous paint.
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What should be the correct electrolyte level in a properly serviced battery?
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It should be approximately 3/8 inches above the plates. If the battery has baffle plates above the
cell plates, the electrolyte level should be up to the hole in the baffle plate in each cell. |
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What is paralleling generators?
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This is when two or more generators are operated at the same time to supply power for a load
that must be shared equally. |
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Describe a no-trip circuit breaker (trip free).
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It is a breaker that cannot be reset while in flight.
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