Practicing Success
Practicing Success
CUET Preparation Today
A copper wire is stretched to make it 0.1 % longer. The percentage change in its resistance is |
0.2 % increase 0.2% decrease 0.1 % increase 0.1 % decrease |
0.2 % increase |
$ R = \frac{\rho l}{A} $ $ l.A = V = constant$ $ \Rightarrow R = \frac{\rho l^2}{V} $ $ \frac{\Delta R}{R} = 2\frac{\Delta l}{l} = 0.2 \%$ Increase
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