| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.12 |
| Score | 0% | 62% |
Which of the following can conduct electricity under some conditions but not others?
conductor |
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insulator |
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resistor |
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semiconductor |
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.
In an electronic circuit, a thermocouple can be used to:
keep the circuit at a designated safe temperature |
|
increase or decrease the temperature of a component in the circuit |
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open or close a circuit at a designated temperature |
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link the temperature of one component in the circuit to that of another component in the circuit |
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.
An engineer who wants to document an electric circuit would create which of the following?
a blueprint |
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a layout |
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a matrix |
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a schematic |
A schematic is the proper name for a drawing of an electric or electronic circuit.
A __________ electric current produces a magnetic field proportional to the amount of current flow.
high voltage |
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moving |
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stationary |
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low voltage |
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.
What is the frequency of most household electrical systems?
110Hz |
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60MHz |
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60Hz |
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110V |
Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances. Most households use electricity with a frequency of 60Hz.