| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.56 |
| Score | 0% | 71% |
An amplifier is most similar in function to which of the following:
transistor |
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step-up transformer |
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capacitor |
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step-down transformer |
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.
Why does current in an electric circuit create heat?
heat is created when the current overcomes resistance in the wire |
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the wire in the circuit burns when current passes through |
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voltage is naturally hot |
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current is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
Why is an insulator a poor conductor of electricity?
an insulator has many free electrons |
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an insulator is made of inorganic material |
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an insulator has few free electrons |
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an insulator is made of organic 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.
Voltage and current are __________ proportional.
directly |
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not |
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indirectly |
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inversely |
Voltage (V) is the electrical potential difference between two points. Electrons will flow as current from areas of high potential (concentration of electrons) to areas of low potential. Voltage and current are directly proportional in that the higher the voltage applied to a conductor the higher the current that will result.
| 80 Ω | |
| 40 Ω | |
| 72 Ω | |
| 82 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 = \( \frac{V}{I} \) = \( \frac{760}{9.5} \) = 80 Ω