| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.27 |
| Score | 0% | 65% |
An amplifier is most similar in function to which of the following:
capacitor |
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step-down transformer |
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step-up transformer |
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transistor |
An amplifier is a device that takes a small input signal and creates a larger output signal. This makes it most similar to a step-up transformer which takes a smaller input voltage and creates a larger output voltage.
In metals, increasing the temperature typically _____________ conductivity.
increases |
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eliminates |
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does nothing to |
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decreases |
All conductors have resistance and the amount of resistance varies with the element. Metals exhibit increased resistance (and, therefore, lower conductivity) as their temperature increases.
The ampere is a unit of measurement for:
power |
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inductance |
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energy |
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current |
Current is the rate of flow of electrons per unit time and is measured in amperes (A). A coulomb (C) is the quantity of electricity conveyed in one second by a current of one ampere.
The valence shell of n insulator is how full of electrons?
more than half full |
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less than half full |
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empty |
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half full |
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.
Why does current in an electric circuit create heat?
the wire in the circuit burns when current passes through |
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voltage is naturally hot |
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heat is created when the current overcomes resistance in the wire |
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current is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.