Question

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

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

Answer 1

Answer: (D)

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