Q9 the energy required to create a lattice vacancy in a crystal is equal to l ev. the ratio of the number den

Q9 The energy required to create a lattice vacancy in a crystal is equal to l eV. The ratio of the number densities of vacancies n(1200 K)/n(300 K) when the crystal is at equilibrium at 1200 K and 300 K, respectively, is approximately (a) exp(-30) (b) exp(-15) (c) exp(15) (d) exp(30) Ans. (d)