Answer the following questions related to absorption and emission of thermal radiation.
a. (i) Define absorptive power aλ for a surface at wavelength λ.
b. (ii) State the qualitative relationship between absorptive power and emissive power for a body in thermal equilibrium with its surroundings.
c. (iii) What is the numerical value of the absorptive power of an ideal blackbody at any wavelength?