MHT CET202616 April 2026Evening ShiftPhysicsSemiconductorsActual
Electrical conductivity of insulators is
Options
- Aexactly zero
- Bextremely large
- Cextremely small
- Dsometimes small and sometimes large
Correct answer
C. extremely small
Step-by-step solution
Insulators are materials that offer very high resistance to the flow of electric current. Their energy band gap is very large (typically greater than 3 eV ), which means there are almost no free electrons available for conduction at room temperature. As a result, the electrical conductivity of insulators is not exactly zero but is extremely small, typically in the range of 10⁻²⁰ to 10⁻¹⁰ , ⁻¹ m ⁻¹ . Answer: extremely small