Q106 / 150 · MHT CET 2026 (18 April Shift 2) · Physics
For intrinsic semiconductor, if $n_h$ and $n_e$ represent the number of holes per unit volume and the number of free electrons per unit volume respectively then
- A$n_h < n_e$
- B$n_h > n_e$
- Correct answerC$n_h = n_e$
- D$n_h \neq n_e$
Solution
In an intrinsic semiconductor, charge carriers are generated by the thermal excitation of electrons from the valence band to the conduction band.
Every time an electron is excited to the conduction band, it leaves behind exactly one hole in the valence band.
Therefore, the number of free electrons per unit volume ($n_e$) is always equal to the number of holes per unit volume ($n_h$).
Thus, $n_h = n_e$.
Answer: $n_h = n_e$
Every time an electron is excited to the conduction band, it leaves behind exactly one hole in the valence band.
Therefore, the number of free electrons per unit volume ($n_e$) is always equal to the number of holes per unit volume ($n_h$).
Thus, $n_h = n_e$.
Answer: $n_h = n_e$
Hence, the correct answer is option: 'C'.