Which cell differs from the fundamental principle point of view?

Unlike dry cell,the mercury cell has a constant cell potential throughout its useful life. Why?

Which of the following statements is true for the electrochemical $Daniel$ cell?

If $\Lambda _{NaCl}^{o}=126\,S\,cm^{2}mol^{-1}$,$\Lambda _{KBr}^{o}=152\,S\,cm^{2}mol^{-1}$,and $\Lambda _{KCl}^{o}=150\,S\,cm^{2}mol^{-1}$,then find $\Lambda ^{o}_{NaBr}$ in $S\,cm^{2}mol^{-1}$.

What is a galvanic cell? Give the half-cell reactions of a Daniell cell and explain a redox couple.

The chemical reaction,$2AgCl_{(s)} + H_{2(g)} \to 2HCl_{(aq)} + 2Ag_{(s)}$ taking place in a galvanic cell is represented by the notation: