Select the incorrect option,when a lead storage battery is discharged $-$

The equilibrium constant for the reaction $Zn_{(s)} + Sn^{2+}_{(aq)} \rightleftharpoons Zn^{2+}_{(aq)} + Sn_{(s)}$ is $1 \times 10^{20}$ at $298 \ K$. The magnitude of standard electrode potential of $Sn/Sn^{2+}$ if $E_{Zn^{2+}/Zn}^0 = -0.76 \ V$ is $............ \times 10^{-2} \ V$. (Nearest integer)
Given : $\frac{2.303 \ RT}{F} = 0.059 \ V$

Which solution is filled in a salt bridge?

The extent of charge of a lead accumulator is determined by

Which of the following formulae is used to obtain the value of $E_{\text{cell}}^{\circ}$ for a reaction taking place in a Dry cell?

Why is a finely divided particle layer of $Pt$ and $Pd$ provided on the electrodes of a fuel cell?