Q 12-03-122JEE MainJEE Main 2023 (31 Jan, Shift 1)Easy
Two identical cells, when connected either in parallel or in series give same current in an external resistance $5\ \Omega$. The internal resistance of each cell will be ______ $\Omega$.
Numerical value type. Enter your answer.
Answer: 5
Series: $I=\dfrac{2E}{5+2r}$. Parallel: $I=\dfrac{E}{5+r/2}=\dfrac{2E}{10+r}$.
Equal currents: $5+2r=10+r\Rightarrow r=5\ \Omega$.
Solution by Sreeraj P, M.Sc Physics