Question

If the conductivity of the material lies in the range \(10^2 - 10^8 \, \Omega^{-1}m^{-1}\), then it is a

• A. insulator
• B. semiconductor
• C. superconductor
• D. dielectric
• E. metal

Hint:

Metals have high conductivity and typically fall in the range \(10^2 - 10^8 \, \Omega^{-1}m^{-1}\).

Answer 1

Answer: (E)

The conductivity of materials can be categorized into different types:
- Materials with very low conductivity (\(<10^{-8} \, \Omega^{-1}m^{-1}\)) are called insulators.
- Materials with conductivity in the range of \(10^{-8} \, \Omega^{-1}m^{-1}\) to \(10^2 \, \Omega^{-1}m^{-1}\) are called semiconductors.
- Materials with very high conductivity (\(>10^8 \, \Omega^{-1}m^{-1}\)) are typically metals.
- Superconductors have zero resistance at very low temperatures, and dielectrics are insulating materials that do not conduct electricity.
Given the conductivity range \(10^2 - 10^8 \, \Omega^{-1}m^{-1}\), this falls under the category of metals.
Thus, the correct answer is: \(\boxed{{metal}}\).