Question

............. is having highest thermal conductivity.

• A. Copper metal
• B. Silver metal
• C. Asbestos material
• D. Mild steel

Hint:

While silver has the highest thermal conductivity of any metal, copper is much more widely used in industrial heat exchangers because it is far more cost-effective.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Thermal conductivity (\(k\)) is a physical property of a material that measures its capacity to conduct heat.
Highly structured materials with high free-electron mobility tend to exhibit high thermal conductivities.

Step 2: Detailed Explanation:
Let us compare the approximate thermal conductivity values at room temperature (\(300\ \text{K}\)):
1. Silver metal: \(k \approx 429\ \text{W/m}\cdot\text{K}\)
2. Copper metal: \(k \approx 401\ \text{W/m}\cdot\text{K}\)
3. Mild steel: \(k \approx 50\ \text{W/m}\cdot\text{K}\)
4. Asbestos material: \(k \approx 0.15\ \text{W/m}\cdot\text{K}\) (highly insulating material)
Among all solid metals, pure silver possesses the highest thermal conductivity and electrical conductivity due to its lattice structure and free-electron concentration.

Step 3: Final Answer:
Among the given options, Silver metal has the highest thermal conductivity.