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 heat flow. The mathematical form of thermal resistivity is as follows:
Thermal conductivity formula
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 the 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 |
Frequently Asked Questions – FAQs
What is heat energy?
Heat energy is caused by the movement of particles like atoms, ions, or molecules in gases, liquids and solids. Heat energy can be transmitted from one body to another. The flow or transfer of energy due to the variation in temperature between two bodies is called heat.
What is meant by conductivity?
In thermodynamics, conductivity is a body’s ability to conduct heat through its physical structure.
What is meant by thermal conductivity?
Thermal conductivity is defined as the transportation of energy due to the random movement of molecules across the temperature gradient. In other words, it is defined as the measure of a body’s ability to conduct heat. It is represented by the symbol k.
What is the SI unit of thermal conductivity?
The SI unit of thermal conductivity is watts per meter-kelvin (Wm-1K-1).
What is the thermal conductivity of pure aluminium at 20°?
The thermal conductivity of pure aluminium at 20° is 204 Wm-1 K-1.