In a semiconductor, there are:

(A) no free electrons at any temperature
(B) no free electrons at 0 K
(C) number of free electrons increase with temperature
(D) number of free electrons decrease with temperature

Choose the correct answer from the options given below:

(B) and (C) only

The correct answer is Option (2) → (B) and (C) only

B. Yes, there are no free $e^-$ in a semiconductor at absolute OK. This is because, the electrons in the valence band do not have energy to jump to conduction band.

C. Yes, the number of free electrons increases with temperature because the band in semiconductor break down, creating hole and free electrons.