We know , vacancy concentration is given by :
[tex]\dfrac{N_v}{N_t}=e^-({\dfrac{Qv}{kT}})[/tex]
Here , [tex]k=8.62\times 10^{-5}\ eV/atom \ K[/tex] . ( Boltzmann's constant )
T = Absolute temperature in Kelvin .
Now ,
[tex]\dfrac{(\dfrac{N_v}{N_t})_{1232\ K}}{(\dfrac{N_v}{N_t})_{298\ K}}\\\\\\=\dfrac{2.087\times 10^{-4}}{6.08 \times 10^{-16}}\\\\=3.432\times 10^{11}[/tex]
Hence , this is the required solution .
