| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
The joule is a unit of measurement for:
energy |
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capacitance |
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power |
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resistance |
The joule is a unit of measurement for energy.
The formula specifying Ohm's law is which of the following?
V = IR |
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V = I2R |
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\(V = {R \over I}\) |
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\(V = {I \over R}\) |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Silver and gold are among the most highly conductive elements. Why is copper used much more often as a conductor in electrical circuits?
copper is durable and relatively cheap |
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silver and gold are brittle |
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all of these |
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silver and gold are costly |
All conductors have resistance and the amount of resistance varies with the element. But, resistance isn't the only consideration when choosing a conductor as the most highly conductive elements like silver and gold are also more expensive and more brittle than slightly less conductive elements like copper. A balance needs to be struck between the electrical qualities of a material and its cost and durability.
In household electrical wiring, which color of insulation indicates the 'hot' wire?
black |
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white |
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red |
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green |
In the NM cable used for wiring homes, each cable has three wires inside a sheath with each wire covered in a different color of insulation to indicate its type. The wire with the black insulation is the 'hot' wire, white is the neutral wire, and the ground wire is either covered in green insulation or left bare.
An engineer who wants to document an electric circuit would create which of the following?
a blueprint |
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a layout |
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a schematic |
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a matrix |
A schematic is the proper name for a drawing of an electric or electronic circuit.