Assertion (A) Cu is less reactive than hydrogen.

Reason $(R) \mathrm{E}_{\mathrm{Cu}^{2+} / \mathrm{Cu}}^{\mathrm{S}}$ is negative.

Assertion (A) $\mathrm{E}_{\text {cell }}$ should have a positive value for the cell to function.

Reason (R) $\mathrm{E}_{\text {cathode }}<\mathrm{E}_{\text {anode }}$

Assertion (A) Conductivity of all electrolytes decreases on dilution.

Reason (R) On dilution number of ions per unit volume decreases.

Assertion (A) $\Lambda_m$ for weak electrolytes shows a sharp increase when the electrolytic solution is diluted.

Reason (R) For weak electrolytes degree of dissociation increases with dilution of solution.

Assertion (A) Mercury cell does not give steady potential.

Reason (R) In the cell reaction, ions are not involved in solution.