Question

The expression for mean energy is given by ________

(a) \(\frac{3}{5}NE_F\)

(b) \(\frac{2}{5}NE_F\)

(c) \(\frac{3}{5}E_F\)

(d) \(\frac{2}{5}E_F\)

This question was posed to me during an interview.

Question is taken from Fermi-Dirac Distribution in division Quantum Physics of Engineering Physics I

Answer 1

The correct choice is (a) \(\frac{3}{5}NE_F\)

Easiest explanation: The expression for the mean energy of an electron at absolute zero is given by \(\frac{3}{5}NE_F\). The expression \(\frac{3}{5}E_F\) is called the zero point energy.