Question

There is no hole current in good conductors because they

• A. have large forbidden energy gap.
• B. have overlapping valence and conduction bands.
• C. are full of electrons.
• D. have no valence band.

Hint:

In a good conductor the valence and conduction bands overlap, so there is no separate valence band to leave holes in.

Answer 1

The Correct Option is B

Step 1: Check Each Option
A large forbidden gap describes an insulator, not a conductor.
A conductor does have a valence band, and it is not simply full of electrons.

Step 2: Remaining Option
Only the overlap of valence and conduction bands removes the gap and the need for holes.

Step 3: Result
This is option (B).

Final Answer:
The overlap of the two bands explains the absence of hole current. \[ \boxed{\text{(B) }\text{have overlapping valence and conduction bands.}} \]