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

The specific conductivity of $N/10$ $KCl$ solution at $20 \, ^oC$ is $0.012 \, \Omega^{-1} \, cm^{-1}$ and the resistance of the solution in the cell at $20 \, ^oC$ is $56 \, \Omega$. The cell constant is ........... $cm^{-1}$.

Which of the following expressions correctly represents the equivalent conductance at infinite dilution of $Al_2(SO_4)_3$? Given that $\Lambda_{Al^{3+}}^o$ and $\Lambda_{SO_4^{2-}}^o$ are the equivalent conductances at infinite dilution of the respective ions.

Resistance of $0.1\, M\, KCl$ solution in a conductance cell is $300\, \Omega$ and conductivity is $0.013\, S\, cm^{-1}$. The value of cell constant is

Which among the following statements is true for conductivity?

Molar conductivity of a weak acid $HQ$ of concentration $0.18 \ M$ was found to be $1/30$ of the molar conductivity of another weak acid $HZ$ with concentration of $0.02 \ M$. If $\lambda_{Q^{-}}^0 = \lambda_{Z^{-}}^0$, then the difference of the $pK_a$ values of the two weak acids $(pK_a(HQ) - pK_a(HZ))$ is . . . . . . (Nearest integer).
[Given: degree of dissociation $(\alpha)$ $\ll 1$ for both weak acids, $\lambda^0$: limiting molar conductivity of ions]