Energy Bands in Solids question from MHT CET 2026 (15 May, Shift 1)

Answer: (a)

1. In a semiconductor the band gap is small (about $1\text{ eV}$).
2. At room temperature some electrons get thermal energy to jump from the valence band to the conduction band.
3. They leave holes behind, so the valence band is partially empty and the conduction band is partially filled.
4. So the answer is (a).