COMEDK · Physics · 19. Current Electricity
If the potential difference across the internal resistance \(r_{1}\) is equal to the \(\operatorname{emf} E\) of the battery, then
- A \(R=r_{1}+r_{2}\)
- B \(R=\frac{r_{1}}{r_{2}}\)
- C \(R=r_{1}-r_{2}\)
- D \(R=\frac{r_{2}}{r_{1}^{*}}\)
Answer & Solution
Correct Answer
(C) \(R=r_{1}-r_{2}\)
Step-by-step Solution
Detailed explanation
Total emf of circuit, \(E_{T}=E+E=2 E\) Total resistance of circuit, \(R_{T}=r_{1}+r_{2}+R\) Current flowing through the circuit, \(i=\frac{E_{T}}{R_{T}}=\frac{2 E}{r_{1}+r_{2}+R}...(i)\) As per question \(E=i r_{1}\) \(\Rightarrow \quad i=\frac{E}{r_{1}}...(ii)\) From Eqs. (i)…
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