The length of a uniform wire is doubled and its cross-sectional area is halved. Its resistance becomes
Atwice the original.
Bfour times the original.CORRECT
Cone quarter of the original.
Dunchanged.
JUPEBPhysicsCurrent Electricity
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Why the answer is B, and why the others tempt you.
$R = \dfrac{\rho L}{A}$. Doubling $L$ doubles $R$ and halving $A$ doubles it again, so the resistance becomes four times as large. Considering only one of the two changes gives twice.
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