Joule's law | Statement | Formula

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The principle of Joule's law is that at a constant temperature the internal energy of an ideal gas is independent of volume. 

Statement of Joule's Law:


The change of internal energy of a perfect gas is directly proportional to the change of temperature. 

Let we see above statement in mathematical form.

Formula:


dE ∞ dT or dE = m c dT

Where m = mass of the gas

c = Constant of proportionality, also known as specific heat

Notes:

 We see that its internal energy, as well as temperature, does not change as the gas expands, without doing any external work and without taking in or giving our heat.

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