CUET Preparation Today
A copper wire of resistance $ 4\Omega$ is melted and redrawn to thrice its original length. The resistance of stretched wire is |
$16\Omega$ $24\Omega$ $36\Omega$ $ 48 \Omega$ |
$36\Omega$ |
$ R'= \frac{l'2}{l^2} R = 9\times 4\Omega = 36\Omega$ |
