JEE Mains · Physics · STD 12 - 3. current electricity
To measure the internal resistance of a battery, potentiometer is used. For \(\mathrm{R}=10 \Omega\), the balance point is observed at \(\ell=500 \mathrm{~cm}\) and for \(\mathrm{R}=1 \Omega\) the balance point is observed at \(\ell=400 \mathrm{~cm}\). The internal resistance of the battery is approximately _______.
- A \(0.2 \Omega\)
- B \(0.4 \Omega\)
- C \(0.1 \Omega\)
- D \(0.3 \Omega\)
Answer & Solution
Correct Answer
(D) \(0.3 \Omega\)
Step-by-step Solution
Detailed explanation
Let potential gradient be \(\lambda\). \(\therefore \mathrm{i} \times 10=\lambda \times 500=\varepsilon-\mathrm{ir}_{\mathrm{s}}\) \(\Rightarrow 500 \lambda=\varepsilon-50 \lambda \mathrm{r}_{\mathrm{s}}\) Also,…
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