$A$ hypothetical electrochemical cell is shown below.
$A \,|\, A^{+} \,(x \ M)\, ||\, B^{+} \,(y \ M)\, |\, B$
The $emf$ measured is $+ 0.20 \ V.$ The cell reaction is

$A$ button cell used in watches functions as follows:
$Zn_{(s)} + Ag_2O_{(s)} + H_2O_{(l)} \rightarrow 2Ag_{(s)} + Zn^{2+}_{(aq)} + 2OH^{-}_{(aq)}$
If the half-cell potentials are:
$Zn^{2+}_{(aq)} + 2e^- \rightarrow Zn_{(s)} \,;\, E^o = -0.76 \, V$
$Ag_2O_{(s)} + H_2O_{(l)} + 2e^- \rightarrow 2Ag_{(s)} + 2OH^{-}_{(aq)} \,;\, E^o = 0.34 \, V$
The cell potential will be $..........$ $V.$

For the cell $Cu_{(s)} | Cu^{2+}_{(aq)} (1 \ M) || Zn^{2+}_{(aq)} (1 \ M) | Zn_{(s)}$,given $E^{\circ}_{Zn^{2+}/Zn} = -0.76 \ V$ and $E^{\circ}_{Cu^{2+}/Cu} = 0.34 \ V$,the cell reaction is:

If less than $1.1 \ V$ external opposite current is passed through the Daniell cell,for such condition answer the following questions :
$(1)$ What is the cell potential ?
$(2)$ What is the type of cell ?

The energy conversion involved in a galvanic cell is

Give the anodic,cathodic,and overall reactions of a hydrogen-oxygen fuel cell.