| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.67 |
| Score | 0% | 73% |
Which of the following can conduct electricity under some conditions but not others?
insulator |
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conductor |
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semiconductor |
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resistor |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.
Which of the following will increase the magnetic field produced by the electric current in a wire?
wind the wire into a coil |
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wrap the wire around a ceramic core |
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construct the wire from conductive material |
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construct the wire from insulative 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.
Which of the following is not a purpose of a resistor in an electrical circuit?
control the voltage in the circuit |
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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 |
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.
A diode to an electronic circuit is like a _______________ to a city?
parking lot |
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one-way street |
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highway |
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traffic light |
A diode allows current to pass easily in one direction and blocks current in the other direction.
Which of these materials is not a good conductor of electricity?
gold |
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tin |
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copper |
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air |
All conductors have resistance and the amount of resistance varies with the element. In general, metals make the best conductors of electricity and non-metals make the worst conductors of electricity.