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JEE Main 2023 (12 Apr, Shift 1) · Ohm's Law, Resistivity & Temperature

Ohm's Law, Resistivity & Temperature question from JEE Main 2023 (12 Apr, Shift 1)

Q21JEE Main 2023 · 12 APR · SHIFT 1Medium

Ohm's Law, Resistivity & Temperature

A wire of resistance $160\ \Omega$ is melted and drawn in a wire of one-fourth of its length. The new resistance of the wire will be

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Answer: (d)

Volume constant: $l \to l/4$ means $A \to 4A$ , so $R \propto l^2$ .
$R' = 160\times(1/4)^2 = 10\ \Omega$ . The answer is (d).

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