The balancing length for a cell is 560 cm in a potentiometer experiment. When an external resistance of 10 Ω is connected in parallel to the cell, the balancing length changes by 60 cm. If the internal resistance of the cell is N10Ω, where N is an integer then value of N is _____.

$Balancing length l_{1} = 560 cm$

$Change in balancing length (l_{1} - l_{2}) = 60 cm$

$560 - l_{2} = 60$

$∴ l_{2} = 500 cm$

$r = (\frac{ℓ_{1} - ℓ_{2}}{ℓ_{2}}) R$

$\Rightarrow r = 10 \times \frac{60}{500} = \frac{6}{5} = \frac{12}{10} Ω$

The balancing length for a cell is 560 cm in a potentiometer experiment. When an external resistance of 10 $Ω$ is connected in parallel to the cell, the balancing length changes by 60 cm. If the internal resistance of the cell is $\frac{N}{10} Ω$ , where N is an integer then value of N is _____.