Question
How does the resistance of a wire depend on its radius? Explain your answer.
✓
Answer
Resistance of a wire is inversely proportional to the area of cross-section of the wire.
$\begin{aligned} & R \propto \frac{1}{A} \\ & R \propto \frac{1}{\pi r 2}\end{aligned}$
This means if a wire of same length, but of double radius is taken, its resistance is found to be one-fourth.
$\begin{aligned} & R \propto \frac{1}{A} \\ & R \propto \frac{1}{\pi r 2}\end{aligned}$
This means if a wire of same length, but of double radius is taken, its resistance is found to be one-fourth.
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