| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.66 |
| Score | 0% | 73% |
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.
The joule is a unit of measurement for:
capacitance |
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power |
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resistance |
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energy |
The joule is a unit of measurement for energy.
You would measure the amount of voltage between two points in a circuit with a(n):
voltmeter |
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battery |
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reostat |
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ammeter |
Voltage (V) is the electrical potential difference between two points. A voltmeter is used to measure the voltage between two points in a circuit.
This circuit component symbol represents a(n):
inductor |
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transistor |
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diode |
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capacitor |
A diode allows current to pass easily in one direction and blocks current in the other direction. Diodes are commonly used for rectification which is the conversion of alternating current (AC) into direct current (DC). Because a diode only allows current flow in one direction, it will pass either the upper or lower half of AC waves (half-wave rectification) creating pulsating DC. Multiple diodes can be connected together to utilize both halves of the AC signal in full-wave rectification.
Which of the following will increase the magnetic field produced by the electric current in a wire?
construct the wire from insulative material |
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wind the wire into a coil |
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construct the wire from conductive material |
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wrap the wire around a ceramic core |
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.