Cell Combination (series)

Question

n identical cells each emf E and internal resistance r in series (external R). Total emf and internal resistance?

RankGuru · Accepted Answer

1. **EMF in Series**: When cells are connected in series, their EMFs add up to push charge through the circuit effectively. So, $E_{total} = E + E + \dots = nE$.
2. **Resistance in Series**: The internal resistances also act in series along the same path. Thus, $r_{total} = r + r + \dots = nr$.
3. **Total Circuit Resistance**: If an external resistor $R$ is connected, the net resistance is $R + nr$.
4. **Current Formula**: $I = \frac{nE}{R + nr}$.
5. **Conclusion**: For the battery itself, the equivalent EMF is **$nE$** and internal resistance is **$nr$**.

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Cell Combination (series)

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