In a potentiometer experiment it is found that no current flows through the galvanometer when balancing length is 52 cm of potentiometer when shant resistance of $5 \Omega$ is used balancing length becomes 40 cm The internal resistance of cell is

Question

$(a)\;1.5 \Omega \\(b)\;3\; \Omega \\(c)\;\large\frac{52}{5} \; \Omega \\(d)\; 2 \;\Omega$