JEE Mains · Physics · STD 12 - 3. current electricity
Eight copper wire of length \(l\) and diameter \(d\) are joined in parallel to form a single composite conductor of resistance \(R\). If a single copper wire of length \(2\,l\) have the same resistance \((R)\) then its diameter will be \(.....d\).
- A \(3\)
- B \(4\)
- C \(2\)
- D \(1\)
Answer & Solution
Correct Answer
(B) \(4\)
Step-by-step Solution
Detailed explanation
Each wire has resistance \(=\rho \frac{4 \ell}{\pi d ^{2}}=r\) Eight wire in parallel, then equivalent resistance is \(\frac{ r }{8}=\frac{\rho \ell}{2 \pi d ^{2}}\) Single copper wire of length \(2 l\) has resistance…
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