The total intensity emitted by a black body is 56.8 kw/m2. The wavelength at which it emits maximum radiation is

According to Stefan's law, energy per unit area per unit time =σT4=56.8x103T4=5.68×104 5.67×10-8=1012  hence        T=1000K  According to Wien's displacement law λmT= 2.88×10-3mK   where λm = wavelength corresponds to maximum radiation  λm=2.88×10-6m