Question

In semiconductors at a room temperature

• A. the valence band is partially empty and the conduction band is partially filled
• B. the valence band is completely filled and the conduction band is partially filled
• C. the valence band is completely filled
• D. the conduction band is completely empty

Answer 1

Answer: (A)

the valence band is partially empty and the conduction band is partially filled

Answer 2

In semiconductors at room temperature the electrons get enough energy so that they are able to over come the forbidden gap. Thus at room temperature the valence band is partially empty and conduction band is partially filled. Conduction band $n$ semiconductor is completely empty only at $0 \,K$.