| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.30 |
| Score | 0% | 66% |
From what energy do photovoltaic cells produce electrical energy?
magnetic |
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nuclear |
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chemical |
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sun |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.
In an electronic circuit, a thermocouple can be used to:
increase or decrease the temperature of a component in the circuit |
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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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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.
You would measure the amount of voltage between two points in a circuit with a(n):
reostat |
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voltmeter |
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ammeter |
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battery |
Voltage (V) is the electrical potential difference between two points. A voltmeter is used to measure the voltage between two points in a circuit.
Which of the following will increase the magnetic field produced by the electric current in a wire?
wrap the wire around a ceramic core |
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construct the wire from insulative material |
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wind the wire into a coil |
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construct the wire from conductive material |
A moving electric current produces a magnetic field proportional to the amount of current flow. This magnetic field can be made stronger by winding the wire into a coil and further enhanced if done around an iron containing (ferrous) core.
Why is an insulator a poor conductor of electricity?
an insulator is made of organic material |
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an insulator has few free electrons |
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an insulator is made of inorganic material |
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an insulator has many free electrons |
Insulators have valence shells that are more than half full of electrons and, as such, are tightly bound to the nucleus and difficult to move from one atom to another.