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Heat Conduction


Heat Conduction

From the wordweb dictionary, the word ‘conduct’ means guide, lead, impart. So here, we will be talking about how the heat is conducted. Heat conduction only occurs when there is a difference in temperature at two parts of a body or between 2 or more bodies. It is a process of energy transfer between the atoms/molecules in the body.

 You may also relate this concept with the term ‘conductor’ that we’ve always used to it.
Image result for particles vibration heat conduction
Particles vibration in hot and cold region

The process of heat conduction is all about the particles (atoms /molecules) movement. In a hot substance,  the particles move faster  as they have more energy compared to the particles in a cooler substance. The more energetic particles transfer their energy to the slower neighboring particles. This transfer of energy  is heat conduction. This phenomenon can bee seen from the figure above.

 The heat transfer has its own rate (how fast it is transferred), dQ/dt. It depends on the material of the body k, the cross sectional area, A of the heat flow and the temperature gradient, dT/dx. They are all related by an equation:

Knowing that k is known a thermal conductivity, or you maybe simply understand that it is a measure of how good the heat is conducted. If the value of k is high, it means that the rate of heat transfer is fast. The value of k is different for different material. We can compare the comparison of value of k from the table below:
Related image

Silver shows biggest value of k, while stainless steel has lowest of that. Hence, we can say, silver is the best heat conductor out of the list.

Apart from k, the cross sectional area A also plays important role in allowing the heat transfer. If the area is bigger, the rate of heat transfer is higher as they are directly proportional. Please note that , if the material is a cylindrical wire in form, the cross sectional area is the area of a circle.


The cross sectional area

Thank you,

Mdm Ummi Atiah KMPk

~ May it Benefits You ➽💕

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