Which among the following is the $CORRECT$ formula for the determination of cell constant?

Solutions of two electrolytes $A$ and $B$ are diluted. The $\Lambda_m$ of $B$ increases $1.5$ times while that of $A$ increases $25$ times. Which of the two is a strong electrolyte? Justify your answer.

The limiting molar conductivities of the given electrolytes at $298 \ K$ follow the order: $\lambda^{\circ}_{(K^{+})} = 73.5, \lambda^{\circ}_{(Cl^{-})} = 76.3, \lambda^{\circ}_{(Ca^{2+})} = 119.0, \lambda^{\circ}_{(SO_{4}^{2-})} = 160.0 \ S \ cm^{2} \ mol^{-1}$.

Write a note on molar conductivity $(\Lambda_{m})$ of a solution.

The specific conductance of $0.05 \ M$ $NaOH$ solution is $0.0115 \ S \ cm^{-1}$. What is its molar conductance $(\Lambda_{m})$ in $S \ cm^2 \ mol^{-1}$?

If the equivalent conductance of $1 \ M$ benzoic acid is $12.8 \ \Omega^{-1} \ cm^2 \ eq^{-1}$ and the equivalent conductances of benzoate ion and $H^{+}$ ion are $42$ and $288.42 \ \Omega^{-1} \ cm^2 \ eq^{-1}$ respectively,its degree of dissociation is ............. $\%$