Question:
The resistance of a wire is R. It is bent at the middle by 180^∘ and both the ends are twisted together to make a shorter wire. The resistance of the new wire is
The resistance of a wire is R. It is bent at the middle by 180^∘ and both the ends are twisted together to make a shorter wire. The resistance of the new wire is
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Halving the length reduces resistance by half, while doubling the area reduces it further by half.
Updated On: Mar 20, 2026
- \(2R\)
- \( \dfrac{R}{2} \)
- \( \dfrac{R}{4} \)
- (R)/(8)
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The Correct Option is C
Solution and Explanation
When the wire is bent at the middle and twisted, its length becomes half and the effective cross-sectional area becomes double.
Since
R=ρ (L)/(A),
the new resistance R' is
R'=ρ (L/2)/(2A)=(R)/(4).
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