Select the incorrect statement for a dry cell.

In fuel cells,$Pt-Pd$ are used as catalysts. Identify the full names of these catalysts.

Observe the following statements about a dry cell:
$I$. It is a primary battery.
$II$. Zinc vessel acts as cathode.
$III$. $A$ paste of moist $NH_4Cl$,$MnO_2$ and $ZnCl_2$ is present between two electrodes.
$IV$. The potential of this cell is $1.5 \ V$.
The correct statements are:

The zinc/silver oxide cell is used in electric watches. The reaction is as follows:
$Zn(s) + Ag_2O(s) + H_2O(l) \rightarrow Zn^{2+}(aq) + 2Ag(s) + 2OH^-(aq)$
Given:
$Zn^{2+} + 2e^- \rightarrow Zn ; E^{\circ} = -0.760 \, V$
$Ag_2O + H_2O + 2e^- \rightarrow 2Ag + 2OH^- ; E^{\circ} = 0.344 \, V$
If $F = 96,500 \, C \, mol^{-1}$,the $\Delta G^{\circ}$ of the cell will be $....$ (in $kJ \, mol^{-1}$)

Light can be converted into electricity with the help of a ......... .

Give advantages of fuel cell.