| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
A capacitor is often used for which of the following purposes?
to maintain power in a circuit when the primary power source is disconnected |
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to convert alternating current into direct current |
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to allow a small amount of current to control a large amount of current |
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as a primary power source |
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.
| 30 Ω | |
| 15 Ω | |
| 33 Ω | |
| 27 Ω |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for resistance, R = \( \frac{V}{I} \) = \( \frac{255}{8.5} \) = 30 Ω
Which of the following is a characteristic of batteries connected in parallel?
total current equals the sum of the individual battery currents |
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total current equals the average of the individual battery currents |
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one connection is made between each adjacent battery |
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the positive terminal of one battery is connected to the negative terminal of the next |
You can multiply the voltage or the current supplied by individual batteries by connecting them together either in series or in parallel. The characteristics of batteries connected in parallel are that total voltage equals the average of the individual battery voltages, total current equals the sum of the individual battery currents, the positive terminal of one battery is connected to the positive terminal of the next, the negative terminal of one battery is connected to the negative terminal of the next, and two connections are made between each adjacent battery.
All electricity is the movement of which subatomic particles?
nuclei |
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neutrons |
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protons |
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electrons |
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 diameter of a number 12 wire is __________ the diameter of a number 6 wire?
more than |
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less than |
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triple |
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double |
The larger the number the smaller the diameter of the wire. So, the diameter of a number 12 wire is less than the diameter of a number 6 wire.