State : (a) Wien's displacement law, and (b) first law of thermodynamics.

Explanation

(a) Wien's desplacement law states that the wavelength for which emissive power of black body is maximum is inversel propoetional to the absolute temperatiur of the black body .
`lamda_("max")prop1/T`
` :." "lamda_("max")=bxx1/t`
Where, b = Wien's constant.
(b) The first law of termodyynamics between any two states fo equlibrium states that the change in internal energy is equal to the difference of the heat transfer into the systemp and work done by the system. Thus, in simpler terms, energy can be changed for one form to anothyyer but it cannot be created or destroyed. Hence, energy is always conserved.