Q 12-03-053JEE MainJEE Main 2026 (5 Apr, Shift 2)Easy
When an external resistance of $5\ \Omega$ is connected across terminals of a cell, a current of $0.25$ A flows through it. When the $5\ \Omega$ resistor is replaced by a $2\ \Omega$ resistor, a current of $0.5$ A flows through it. The internal resistance of the cell is ______ $\Omega$.
Numerical value type. Enter your answer.
Answer: 1
$E = 0.25(5 + r) = 0.5(2 + r)$.
$1.25 + 0.25r = 1 + 0.5r \Rightarrow r = 1\ \Omega$.
Solution by Sreeraj P, M.Sc Physics