Ncert Exercises & Solutions

Correct statement among the following regarding conductivity in solids is -

1. $κ_{metals} ≫ κ_{insulators} < κ_{semiconductors}$

2. $κ_{metals} ≪ κ_{insulators} < κ_{semiconductors}$

3. $κ_{metals}, κ_{semiconductors} > κ_{insulators} = zero$

4. $κ_{metals} < κ_{semiconductors} > κ_{insulators} \neq zero$

HINT: In an insulator, an energy gap exists between the conduction band and valence band is high.

Explanation:

The conductivity of metal, insulators, and semiconductors can be represented in the term of

κ

(Kappa) which depends upon the energy gap between the valence band and conduction band.

Hence, the correct order is

κ_{metals} ≫ κ_{insulators} < κ_{semiconductors}