Question

In the series combination of $n$ cells each cell having emf $\varepsilon$ and internal resistance $r$. If three cells are wrongly connected, then total emf and internal resistance of this combination will be

• A. $n\varepsilon$, $\left(nr-3r\right)$
• B. $\left(n\varepsilon-2\varepsilon\right)$, $nr$
• C. $\left(n\varepsilon-4\varepsilon\right)$, $nr$
• D. $\left(n\varepsilon-6\varepsilon\right)$, $nr$

Answer 1

Answer: (D)

$\left(n\varepsilon-6\varepsilon\right)$, $nr$

Answer 2

Since due to wrong connection of each cell the total emf reduced to $2\varepsilon$ then for wrong connection of three cells the total emf will reduced to $\left(n\varepsilon-6\varepsilon\right)$ whereas the total or equivalent resistance of cell combination will be $nr$.