If the conductivity of mercury at $0^\circ C $ is $1.07 \times 10^6 Sm^{-1} $ and the resistance of a cell containing mercury is $0.243 \Omega $, then the cell constant of the cell is $x \times 10^4 m^{-1} $. (Nearest integer)

*Solution*

$R=\frac {K_{cell}}{\kappa }$

Or, $K_{cell} = 0.243 \times 1.07 \times 10^6 \approx 26 \times 10^4 m^{-1} $

Answer: 26