| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.89 |
| Score | 0% | 58% |
The valence shell of a semiconductor is how full of electrons?
half full |
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empty |
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less than half full |
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more than half full |
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.
What kind of diode allows current to flow in the opposite direction once a certain voltage threshold is reached?
standard diode |
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light emitting diode |
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v-type diode |
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zener diode |
A diode allows current to pass easily in one direction and blocks current in the other direction. A zener diode is a diode which allows current to flow in one direction as normal and will also allow current flow in the reverse direction when the voltage is above a certain value. This value is called the breakdown voltage.
In an electronic circuit, a thermocouple can be used to:
open or close a circuit at a designated temperature |
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increase or decrease the temperature of a component in the circuit |
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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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keep the circuit at a designated safe 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.
| 16 Ω | |
| 150 Ω | |
| 50 Ω | |
| 100 Ω |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for resistance, R = \( \frac{V}{I} \) = \( \frac{475}{9.5} \) = 50 Ω
In electrical wiring, which of the following are proportional?
the diameter of the wire and the amount of the current |
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the diameter of the wire and the amount of the voltage |
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the length of the wire and the amount of the voltage |
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the length of the wire and the amount of the current |
Current flow through a wire increases the temperature of the wire. If too small a wire is used, the wire will heat up causing a loss in conductivity and possibly a fire. The thicker in diameter a wire is, the more current it can carry without overheating.