| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.46 |
| Score | 0% | 69% |
A capacitor is often used for which of the following purposes?
as a primary power source |
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to allow a small amount of current to control a large amount of current |
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to maintain power in a circuit when the primary power source is disconnected |
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to convert alternating current into direct current |
Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.
The conductivity of an element depends on how many electrons occupy which electron shell?
middle |
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outer |
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inner |
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first |
All electricity is the movement of electrons which are subatomic particles that orbit the nucleus of an atom. Electrons occupy various energy levels called shells and how well an element enables the flow of electrons depends on how many electrons occupy its outer (valence) electron shell.
The voltage output of a transformer primarily depends on which of the following?
the diameter of the wire in the coils |
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the number of turns in the wire of the coils |
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the diameter of the coils |
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the conductor used for the wire in the coils |
A transformer utilizes an inductor to increase or decrease the voltage in a circuit. AC flowing in a coil wrapped around an iron core magnetizes the core causing it to produce a magnetic field. This magnetic field generates a voltage in a nearby coil of wire and, depending on the number of turns in the wire of the primary (source) and secondary coils and their proximity, voltage is induced in the secondary coil.
Longer the electrical wires mean _______________ voltage drop.
lesser |
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diminishing |
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greater |
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complete |
Electrical wires have a certain amount of resistance per foot. A longer wire means more resistance and a greater voltage drop.
This circuit diagram represents a(n):
parallel circuit |
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series circuit |
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open circuit |
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series-parallel circuit |
A series circuit has only one path for current to flow. In a series circuit, current (I) is the same throughout the circuit and is equal to the total voltage (V) applied to the circuit divided by the total resistance (R) of the loads in the circuit. The sum of the voltage drops across each resistor in the circuit will equal the total voltage applied to the circuit.