What is the function of a salt bridge in a Daniell cell?

Limiting molar conductivity of $Mg^{2+}$ and $Cl^{-}$ ions in water is $106.0 \ S \ cm^2 \ mol^{-1}$ and $76.3 \ S \ cm^2 \ mol^{-1}$ respectively. The limiting molar conductivity of magnesium chloride (in $S \ cm^2 \ mol^{-1}$) in water is

Which substance is used as an oxidising agent in a nickel-cadmium cell?

Give the chemical reaction when a $Cu$ rod is kept in an $AgNO_{3}$ solution.

In the electrochemical cell $H_{2(g)}, 1 \ atm \ | \ H^+_{(aq)}, 1 \ M \ || \ Cu^{2+}_{(aq)}, 1 \ M \ | \ Cu_{(s)}$,which of the following statements is true?

If less than $1.1 \ V$ external opposite current is passed through the Daniell cell,for such condition answer the following questions :
$(1)$ Give reaction of cathode,anode and redox.
$(2)$ Between $Zn$ and $Cu$ which metal dissolve in solution ?