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Is it true that the speed of electrons in the branches is smaller than in the main wire as the current splits in a parallel circuit? If its true, how does the speed reduce (the mechanism, not because of the laws alone)? If not, then what really causes the smaller current in the branches (and the mechanism too).

Kyle Kanos
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Warren
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1 Answers1

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The answer depends on the wires in the branches and the main wire are made out of and what shapes they have. What you can know for sure is that the sum of currents in the branches is the current in the main wire.

Now the current in the wire is the electron charge density times the average speed of the electrons times the cross sectional area of the wire. Now if the wires are made of the same material throughout, the density of electrons is the same, but the current still depends on the cross sectional area and the electron speed. If each branch has half the the area of the main wire, then the electron speed is the same. However, if the branch wires are each as large as the main wire, then the elections in the branch move slower. As a final example, if the branch wires are very thin, the electrons must move very fast to give the same current.

Brian Moths
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