Write the conductivity range of semiconductors?

Using the data given below find out which of the following is the strongest oxidising agent.

$$\begin{gathered} {\mathrm{E}}_{{\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}/{\mathrm{Cr}}^{3+}}^{⊝}=1.33 \mathrm{V} {\mathrm{E}}_{{\mathrm{Cl}}_2/{\mathrm{Cl}}^{-}}^{⊝}=1.36 \mathrm{V} \\ {\mathrm{E}}_{{\mathrm{MnO}}_4^{-}/{\mathrm{Mn}}^{2+}}^{⊝}=1.51 \mathrm{V} {\mathrm{E}}_{{\mathrm{Cr}}^{3+}/\mathrm{Cr}}^{⊝}=-0.74 \mathrm{V} \end{gathered}$$

Cell equation : $\mathrm{A} + 2{\mathrm{B}}^{-} \to {\mathrm{A}}^{2+} +2\mathrm{B};$

${\mathrm{A}}^{2+}+\hspace{0.17em}2{\mathrm{e}}^{-} \to \mathrm{A}$, ${\mathrm{E}}^{\mathrm{o}} = +0.34 \mathrm{V}$, ${\log }_{10} \mathrm{K} = 15.6$ at $300\mathrm{K}$ for cell reactions find ${\mathrm{E}}^{\mathrm{o}}$ for ${\mathrm{B}}^{+} + {\mathrm{e}}^{-} \to \mathrm{B}$