| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.32 |
| Score | 0% | 66% |
| 43 Ω | |
| 40 Ω | |
| 13 Ω | |
| 80 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 = \( \frac{V}{I} \) = \( \frac{160}{4} \) = 40 Ω
A capacitor is often used for which of the following purposes?
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 |
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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.
An inductor __________ changes in the electric current flowing through it.
enhances |
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eliminates |
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resists |
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doubles |
An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.
What is the voltage of most household electrical systems in the United States?
220V |
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60V |
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110V |
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60Hz |
Most households use electricity with a voltage of 110V.
The farad is a unit of measurement for:
capacitance |
|
inductance |
|
power |
|
energy |
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.