If a black-body is at an equilibrium temperature T of a certain volume. If we increase size of blackbody does the equilibrium temperature of the blackbody will change?
The internal energy per unit mass (the specific internal energy) of a solid is proportional to temperature. The total internal energy equals the internal energy per unit mass times the total mass. Increasing the volume (and thus the mass) of the a solid, in the absence of any heat transfer from the surroundings to the solid, or a black body that generates energy (sum), decreases the internal energy per unit mass. That mean the temperature should decrease. This would apply to any solid, not just a blackbody.
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