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 $5\Omega$, balance is obtained when the cell is connected across 0.4 m of the
wire. Find the internal resistance of the cell.

• A

  $0.5\Omega$

• B

  $1\Omega$

• C

  $1.5\Omega$

• D

  $2\Omega$