Specific resistance of a wire depends on its

An electric current passes through a non-uniform cross section of a wire made of homogeneous and isotropic material. If $j_{\mathrm{A}}$ and $j_{\mathrm{B}}$ be the current densities and $E_{\mathrm{A}}$ and $E_{\mathrm{B}}$ be the electric field intensities at $A$ and $B$, respectively, then,

A wire has a resistance of $2.5\mathrm{ }\mathrm{\Omega }$ at $28 °\mathrm{C}$ and a resistance of $2.9\mathrm{ }\mathrm{\Omega }$ at $100 °\mathrm{C}$. If the temperature coefficient of resistance of the material of the wire is $\frac{1}{n}°{\mathrm{C}}^{-1}$, then what is the value of $n$?

An ideal cell of emf $10 \mathrm{V}$ is connected in circuit shown in figure. Each resistance is $2 \mathrm{\Omega }.$ The potential difference (in $\mathrm{V}$) across the capacitor when it is fully charged is ______.