Question

In energy band diagram of insulators, a band gap and the conduction band is respectively

• A. very high, empty
• B. very low, empty
• C. very high, completely filed
• D. very low, partially filled

Hint:

An insulator has a very wide forbidden gap and nothing in the conduction band.

Answer 1

The Correct Option is A

Step 1: Think about conduction
Current needs free electrons in the conduction band. In an insulator the electrons are stuck in the valence band.

Step 2: Why
They are stuck because the energy gap is very high, so almost no electron gets enough energy to jump. This leaves the conduction band empty.
Hence "very high, empty".

Final Answer:
High gap, empty conduction band. Option (A). \[ \boxed{\text{(A)}} \]