| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.44 |
| Score | 0% | 69% |
Which of the following will increase the magnetic field produced by the electric current in a wire?
construct the wire from conductive material |
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wind the wire into a coil |
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construct the wire from insulative 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.
An inductor __________ changes in the electric current flowing through it.
enhances |
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resists |
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eliminates |
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doubles |
An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.
You would measure the amount of voltage between two points in a circuit with a(n):
ammeter |
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reostat |
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battery |
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voltmeter |
Voltage (V) is the electrical potential difference between two points. A voltmeter is used to measure the voltage between two points in a circuit.
The diameter of a number 12 wire is __________ the diameter of a number 6 wire?
triple |
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less than |
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double |
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more than |
The larger the number the smaller the diameter of the wire. So, the diameter of a number 12 wire is less than the diameter of a number 6 wire.
What type of current flows in only one direction in a circuit?
direct |
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series |
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alternating |
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parallel |
Direct current flows in only one direction in a circuit, from the negative terminal of the voltage source to the positive. A common source of direct current (DC) is a battery.