In an intrinsic semiconductor the energy gap $E_g$ is $1.2\;ev$ . It hole mobility and independent of temperature . What is the ratio between conductivity at $600\;k$ and $300\;k$ Assume that the temperature dependence intrinic concentration $n_i$ is given by $n_i = n_0 exp\bigg(\large\frac{-Eg}{2K_b t}\bigg)$, Where $n_o$ is a Constant and $K_b= 8.62 \times 10^{-5} ev/K$