| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.35 |
| Score | 0% | 67% |
Which of the following statements about electrical resistance is true?
the more resistive the conductor is the slower electron flow will be |
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the more resistive the conductor is the faster electron flow will be |
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electrically conductive materials have no resistive properties |
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the less 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.
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?
series-parallel |
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series |
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perpendicular |
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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.
Why is an insulator a poor conductor of electricity?
an insulator has many free electrons |
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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 |
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.
From what energy do photovoltaic cells produce electrical energy?
nuclear |
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sun |
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chemical |
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magnetic |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.
General current flow in a transistor is from __________ to __________.
collector, emitter |
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collector, base |
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base, emitter |
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base, collector |
The transistor is the foundation of modern electronic devices. It is made entirely from semiconductor material (making it a solid state device) and can serve many different functions in a circuit including acting as a switch, amplifier, or current regulator. A transistor works by allowing a small amount of current applied at the base to control general current flow from collector to emitter through the transistor.