| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.54 |
| Score | 0% | 71% |
Longer the electrical wires mean _______________ voltage drop.
complete |
|
diminishing |
|
lesser |
|
greater |
Electrical wires have a certain amount of resistance per foot. A longer wire means more resistance and a greater voltage drop.
| 90 Ω | |
| 45 Ω | |
| 180 Ω | |
| 99 Ω |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for resistance, R = \( \frac{V}{I} \) = \( \frac{90}{1} \) = 90 Ω
Why does current in an electric circuit create heat?
current is naturally hot |
|
heat is created when the current overcomes resistance in the wire |
|
the wire in the circuit burns when current passes through |
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voltage is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
The valence shell of n insulator is how full of electrons?
empty |
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more than half full |
|
less than half full |
|
half full |
Insulators have valence shells that are more than half full of electrons and, as such, are tightly bound to the nucleus and difficult to move from one atom to another.
Which of the following will increase the magnetic field produced by the electric current in a wire?
wrap the wire around a ceramic core |
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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 |
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.