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Question
Write an expression for the resistance of a conducting wire in terms of its length and area of cross-section.
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Solution
Let R be the resistance of a conducting wire of length l and area of cross-section A. We then have:
R = ρl/A
Here ρ is a constant characteristic of the material of the wire and is called its resistivity. Thus,
Resistance = `(("Resistivity of the material of the wire") xx ("length of thge wire"))/("Area of cross-section of the wire")`
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