(a) Write the name of the cell which is generally used in inverters. Write the reactions taking place at anode and cathode of this cell, when it is in use. OR (b) Explain why electrolysis of an aqueous solution of $ ext{NaCl}$ gives $ ext{H}_2$ gas at cathode and $ ext{Cl}_2$ gas at anode ? Write overall reaction. (Given : $E_{ ext{Na}^+/ ext{Na}}^{\circ} = - 2\cdot71\text{ V}$, $E_{ ext{H}_2 ext{O}/ ext{H}_2}^{\circ} = - 0\cdot83\text{ V}$, $E_{ ext{Cl}_2/2 ext{Cl}^-}^{\circ} = + 1\cdot36\text{ V}$, $E_{ ext{H}^+/ ext{O}_2/ ext{H}_2 ext{O}}^{\circ} = + 1\cdot23\text{ V}$)