What will be the conductivity of pure silicon crystal at 300 K temperature if electron cotter pair at this temperature is  $1\cdot 072\times {10}^{10}/{\mathrm{cm}}^3$ and ${\mathrm{\mu }}_{\mathrm{n}}=1350{\mathrm{cm}}^2/\mathrm{V}-\mathrm{s}$ and ${\mathrm{\mu }}_{\mathrm{p}}=480{\mathrm{cm}}^2/\mathrm{V}-\mathrm{s}?$

• A

  $3\cdot 14\times {10}^{-4}\mathrm{mho}/\mathrm{cm}$

• B

  $\mid 3\cdot 14\times {10}^{-5}\mathrm{mho}/\mathrm{cm}$

• C

  $3\cdot 14\times {10}^{-6}\mathrm{mho}/\mathrm{cm}$

• D

  $3\times {10}^{-6}\mathrm{mho}/\mathrm{cm}$