| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.18 |
| Score | 0% | 64% |
The formula specifying Ohm's law is which of the following?
\(V = {R \over I}\) |
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V = IR |
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V = I2R |
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\(V = {I \over R}\) |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
The most common circuit configuration is:
parallel |
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series-parallel |
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series |
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household |
Circuits are not limited to only series or only parallel configurations. Most circuits contain a mix of series and parallel segments. A good example is a household circuit breaker. Electrical outlets in each section of the house are wired in parallel with the circuit breaker for that section wired in series making it easy to cut off electricity to the parallel parts of the circuit when needed.
A capacitor is often used for which of the following purposes?
to allow a small amount of current to control a large amount of current |
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as a primary power source |
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to convert alternating current into direct current |
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to maintain power in a circuit when the primary power source is disconnected |
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.
In electrical wiring, which of the following are proportional?
the length of the wire and the amount of the current |
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the diameter of the wire and the amount of the current |
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the diameter of the wire and the amount of the voltage |
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the length of the wire and the amount of the voltage |
Current flow through a wire increases the temperature of the wire. If too small a wire is used, the wire will heat up causing a loss in conductivity and possibly a fire. The thicker in diameter a wire is, the more current it can carry without overheating.
The valence shell of a semiconductor is how full of electrons?
empty |
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half full |
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less than half full |
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more than half full |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.