Which of the following net cell reaction takes place in a galvanic cell containing copper electrode and standard hydrogen electrode?

$$ \mathrm{E}^{o}\left(\mathrm{Cu}_{(\mathrm{aq})}^{+2} \mid \mathrm{Cu}_{(\mathrm{s})}\right)=+0.34 \mathrm{~V} $$

Which of the following changes takes place at positive electrode during recharging of lead accumulator?

For the cell reaction, $\mathrm{A}_{(\mathrm{s})}+\mathrm{B}_{(\mathrm{eq})}^{+_2} \longrightarrow \mathrm{~A}_{(\mathrm{eq})}^{+_2}+\mathrm{B}_{(\mathrm{s})}$ if equilibrium constant of reaction is $10^4$ at 298 K . What is standard emf of cell?

If $\mathrm{E}^{-}\left(\mathrm{Cu}_{(a q)}^{+2} \mid \mathrm{Cu}_{(s)}\right)=+0.34 \mathrm{~V}$. What is potential for $\mathrm{Cu}_{(s)} \rightarrow \mathrm{Cu}_{(\mathrm{aq})}^{+2}(0.1 \mathrm{M})+2 \mathrm{e}^{-}$at 298 K ?