Question

The pd difference between 2 terminals of a cell in open circuit was 2.2 v & when it was connected through a resistance of 5 ohm the pd fell to 1.8 v. Find the internal resistanceof the cell

Answer 1

Dear Student,
$$\begin{gathered} Potentialdifferanceacross5ohm=1.8V \\ letinternalresis\tan cer \\ potentialdifferenceacrossrmustbe.4V \\ ascurrentincircuitissame \end{gathered}$$
$$\begin{gathered} i=\frac{potentialdifferenceacross5ohm}{5}=\frac{potentialdifferanceacrossr}{r} \\ \Rightarrow \frac{1.8}{5}=\frac{.4}{r}\Rightarrow r=\frac{5\times .4}{1.8}=1.11ohm \end{gathered}$$
Regard