Resistance of a wire is r ohm. The wire taken is double its length, then its intial resistance in ohm will be

\frac{r}{2}

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4 r

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2 r

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\frac{r}{4}

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Solution

The correct option is C $2 r$
$R = ρ \frac{l}{A}$

$⟹ R \propto l$

Hence, on doubling length, resistance becomes twice that is $2 r$ .

Answer-(C)

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Resistance of a wire is r ohm. The wire taken is double its length, then its intial resistance in ohm will be

The correct option is C 2rR=ρlA⟹R∝lHence, on doubling length, resistance becomes twice that is 2r.Answer-(C)

The correct option is C $2 r$
$R = ρ \frac{l}{A}$

$⟹ R \propto l$

Hence, on doubling length, resistance becomes twice that is $2 r$ .

Answer-(C)