| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.08 |
| Score | 0% | 62% |
From what energy do photovoltaic cells produce electrical energy?
sun |
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nuclear |
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magnetic |
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chemical |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.
In metals, increasing the temperature typically _____________ conductivity.
eliminates |
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increases |
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decreases |
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does nothing to |
All conductors have resistance and the amount of resistance varies with the element. Metals exhibit increased resistance (and, therefore, lower conductivity) as their temperature increases.
In an electronic circuit, a thermocouple can be used to:
keep the circuit at a designated safe temperature |
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link the temperature of one component in the circuit to that of another component in the circuit |
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increase or decrease the temperature of a component in the circuit |
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open or close a circuit at a designated temperature |
A thermocouple is a temperature sensor that consists of two wires made from different conductors. The junction of these two wires produces a voltage based on the temperature difference between them and can be used like a switch to open or close the circuit at a designated temperature.
The ampere is a unit of measurement for:
power |
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inductance |
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current |
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energy |
Current is the rate of flow of electrons per unit time and is measured in amperes (A). A coulomb (C) is the quantity of electricity conveyed in one second by a current of one ampere.
Capacitors store:
electricity |
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current |
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capacitance |
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resistance |
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.