Your Results | Global Average | |
---|---|---|
Questions | 5 | 5 |
Correct | 0 | 3.54 |
Score | 0% | 71% |
Which of these materials is not a good conductor of electricity?
air |
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gold |
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copper |
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tin |
All conductors have resistance and the amount of resistance varies with the element. In general, metals make the best conductors of electricity and non-metals make the worst conductors of electricity.
One of the lights on your Christmas tree burns out and this causes the rest of the lights connected to that strand to go dark. How are the lights in that strand connected?
series-parallel |
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series |
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parallel |
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perpendicular |
Lights connected in series form a chain with each light connecting to adjacent lights via one wire. Therefore, if one of the lights burns out and breaks the series, none of the other lights will receive power and they'll go dark. Lights connected in parallel each connect to the positive and negative nodes of the power source and would not go dark if one of their neighbors burnt out.
The conversion of alternating current (AC) into direct current (DC) is called:
capacitance |
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inductance |
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rectification |
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reactance |
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.
The rate of flow of electrons per unit time is which of the following?
current |
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resistance |
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voltage |
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conductance |
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.
This circuit component symbol represents a(n):
transformer |
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capacitor |
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AC source |
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DC source |
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.