Resistance of a conductivity cell filled with $0.1 \;mol^{-1}KCl$ solution is $100 \Omega$ . If the resistance of the same cell when filled with $0.2\;mol L^{-1}\;KCl$ solution is $520\; \Omega$ . Calculate the conductivity of $0.2 mol L^{-1} \;KCl$ solution . The conductivity of $0.1\;mol L^{-1} KCl$ solution is $1.29\;s.m$