In a potentiometer experiment it is found that no current passes through the galvanometer when the terminals of the cell are connected across `0.52 m` of the potentiometer wire. If the cell is shunted by a resistance of `5Omega` balance is obtained when the cell connected across` 0.4m` of the wire. Find the internal resistance of the cell.
A. `2Omega`
B. `2.5 Omega`
C. `1 Omega`
D. `1.5 Omega`