How and why does external magnetic field/electric effect the internal energy of a sub
In magneto caloric effect, we see that when a substance in an adiabetic closure is exposed to external magnetic field, its temperature increases. But the internal energy of the substance has to be constant so this implies decrease in internal potential energy. However the application of magnetic field can only directly change the external potential energy of the substance as a whole. How it can affect the internal energy of the substance??
For example like gravitational field cant effect the internal energy of the substance..