Question

2. The Fermi energy of an intrinsic semiconductor is undefined.

 A. True

B.  False

Answer 1

The correct answer is the option A - True.

Fermi level energy is the energy which separates the empty levels of the valence band from the occupied states in the conduction band at absolute temperature i.e., at 0 K.

In an intrinsic type of semi-conductor, the number of holes in the valence band is equal to the number of electrons in the conduction band. So, the fermi level of an instrinsic semi-condcutor will range somewhere in between the valence band and the conduction. So, it becomes an undefined as the fermi level is present in the forbidden band.