JEE Mains · Physics · STD 12 - 3. current electricity
In a Wheatstone bridge (see figure) Resistance \(P\) and \(Q\) are approximately equal. When \(R = 400\,\Omega ,\) the bridge is balanced. On interchanging \(P\) and \(Q,\) the value of \(R,\) for balance is \(405\,\Omega .\) The value of \(X\) is close to ................. \(ohm\)
- A \(401.5\)
- B \(404.5\)
- C \(403.5\)
- D \(402.5\)
Answer & Solution
Correct Answer
(D) \(402.5\)
Step-by-step Solution
Detailed explanation
\(\frac{P}{Q}=\frac{400}{s}\) .....\((1)\) and \(\quad \frac{Q}{P}=\frac{405}{5}\) .......\((2)\) Solving \(S^{2}=400 \times 405\) \(\Rightarrow \quad S=402.5\, \Omega\)
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