In batteries and fuel cells,which energy is converted into which energy?

The work done in a galvanic cell is equal to which of the following?

Based on the following information,arrange four metals,$A$,$B$,$C$,and $D$,in order of increasing ability to act as reducing agents:
$(I)$ Only $C$ reacts with $0.10 \ M \ HCl$ to give $H_{2(g)}$.
$(II)$ When $A$ is added to a solution of the other metal ions,metallic $D$ is formed,but not $B$ or $C$.

Which of the following net cell reactions occurs in a galvanic cell containing a cadmium electrode and a standard hydrogen electrode? Given: $E^0_{(Cd^{2+}(aq)|Cd(s))} = -0.403 \text{ V}$.

Give the types and examples of electrodes.

Write a note on hydrogen-oxygen fuel cell.