JEE Mains · Physics · STD 12 - 3. current electricity
The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the wire will be..... \(\%\).
- A \(390\)
- B \(300\)
- C \(370\)
- D \(399\)
Answer & Solution
Correct Answer
(B) \(300\)
Step-by-step Solution
Detailed explanation
\(V ^{\prime}= V\) \(\ell^{\prime} A =\ell A\) \(2 \ell A ^{\prime}=\ell A\) \(A ^{\prime}=\frac{ A }{2}\) \(R =\rho \frac{\ell}{ A } \ldots\,\, (i)\) \(\ell^{\prime}=2 \ell\) \(A ^{\prime}=\frac{ A }{2}\)…
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