B2: (20 Mark) Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 K. Calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. What is the wavelength λ, below which 10% of the emission is concentrated? What is the wavelength 22 above which 10% of the emission is concentrated? Determine the wavelength at which maximum spectral emissive power occurs. What is the irradiation incident on a small object placed inside the enclosure?