| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.56 |
| Score | 0% | 71% |
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.
Resistance is opposition to which of the following?
conductance |
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current |
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impedance |
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voltage |
Resistance is opposition to the flow of current and is measured in ohms (Ω). One ohm is defined as the amount of resistance that will allow one ampere of current to flow if one volt of voltage is applied. As resistance increases, current decreases as resistance and current are inversely proportional.
Which of the following statements about electrical resistance is true?
the more resistive the conductor is the faster electron flow will be |
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the less resistive the conductor is the slower electron flow will be |
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electrically conductive materials have no resistive properties |
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the more resistive the conductor is the slower electron flow will be |
Resistance is opposition to the flow of current. As resistance increases, current decreases as resistance and current are inversely proportional.
Which of the following is not a purpose of a resistor in an electrical circuit?
limit the current in the circuit |
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multiply the current in the circuit |
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moderate the heat in the circuit |
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control the voltage in the circuit |
Resistors can be chosen in a wide variety of values to control the voltage in a circuit, limit the current, or moderate the heat produced by the components in the circuit.
One of the lights on your Christmas tree burns out and this causes the rest of the lights connected to that strand to go dark. How are the lights in that strand connected?
parallel |
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perpendicular |
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series |
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series-parallel |
Lights connected in series form a chain with each light connecting to adjacent lights via one wire. Therefore, if one of the lights burns out and breaks the series, none of the other lights will receive power and they'll go dark. Lights connected in parallel each connect to the positive and negative nodes of the power source and would not go dark if one of their neighbors burnt out.