What Is Thermal Conductivity?
Thermal conductivity is defined as the transportation of energy due to the random movement of molecules across the temperature gradient. In simple words, it is defined as the measure of a material’s ability to conduct heat. It is denoted by k.
The inverse of thermal conductivity is thermal resistivity. It is defined as the temperature difference by which a material can resist the heat flow. The mathematical form of thermal resistivity is as follows:
Thermal conductivity formula
k = Q L /A Δ T
Where,
- k is the thermal conductivity (Wm-1K-1)
- Q is the amount of heat transferred through the material (Js-1)
- A is the area of the body (m2)
- ΔT is the temperature difference (K)
Unit Of Thermal Conductivity
| SI unit of thermal conductivity | Watts per meter-kelvin (W.m-1K-1) |
| Imperial unit of thermal conductivity | BTU.h-1.ft-1.℉-1 |
| Dimensional formula | M1L1T-3Θ-1 |
Thermal Conductivity Of Metals
Following is the table giving information on thermal conductivity of metals when the temperature is measured in °C
| Metal | Temperature in ℃ | Thermal conductivity in Wm-1K-1 |
| Aluminum (pure) | 20 | 204 |
| Beryllium | 20 | 218 |
| Copper (pure) | 20 | 386 |
| Gold | 20 | 315 |
| Iron (pure) | 20 | 73 |
| Lead | 20 | 35 |
| Nickel | 20 | 90 |
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