Correct answer is (d) 5.51 eV
The explanation: Fermi Energy, \(E_F = \frac{h^2}{8m} (\frac{3N}{\pi v})^{2∕3}\)
Here, N /V = 10.5 X 6.02 X 10^23/108
= 5.85 X 10^28 m^-3
Therefore, \(E_F = \frac{6.626 X 6.626}{8 X 9.1} \times 10^{-19} \times \frac{3 \times 5.585}{\pi}^{2∕3}\)
= 8.816 X 10^-19J
= 5.51 eV.