A wire of resistance $12\,ohms$ per meter is bent to form a complete circle of radius $10\, cm.$ The resistance between its two diametrically opposite points, $A$ and $B$ as shown in the figure is
AIPMT 2009, Medium
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Wire of length $2\, \pi \times 0.1\, \mathrm{m}$ of $12 \,\Omega / \mathrm{m}$ is bent to a circle.
Resistance of each part
$=12 \times \pi \times 0.1=1.2\, \pi \,\Omega$
$\therefore \quad$ Resistance between $A$ and $B = 0.6\,\pi \Omega .$
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