| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.48 |
| Score | 0% | 70% |
Direct current flows from the __________ terminal of the voltage source to the __________ terminal.
negative, positive |
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positive, negative |
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negative, negative |
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positive, positive |
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.
Alternating current changes __________ many times each second.
period |
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frequency |
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resistance |
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direction |
In contrast to the constant one-way flow of direct current, alternating current changes direction many times each second. Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances.
Which of the following will increase the magnetic field produced by the electric current in a wire?
wind the wire into a coil |
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construct the wire from insulative material |
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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.
Voltage and current are __________ proportional.
directly |
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not |
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inversely |
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indirectly |
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.
The volt is a unit of measurement for:
capacitance |
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voltage |
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current |
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power |
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.