Write the equation for the equivalent electromotive force (emf) of cells connected in parallel.

(N/A) For $n$ cells connected in parallel,each having an electromotive force (emf) $\varepsilon_i$ and internal resistance $r_i$,the equivalent emf $\varepsilon_{eq}$ is given by the formula:
$\varepsilon_{eq} = \frac{\sum_{i=1}^{n} \frac{\varepsilon_i}{r_i}}{\sum_{i=1}^{n} \frac{1}{r_i}}$
If all cells are identical with emf $\varepsilon$ and internal resistance $r$,the equivalent emf simplifies to:
$\varepsilon_{eq} = \varepsilon$