Two materials, one with ε1 = 0.9 and the other with ε2 = 0.2 areavailable to use as filaments (light sources) for an incandescentlamp. Material 1 can be maintained at 2800 K, whereas material 2can be maintained at 3000 K. Calculate the rate at which radiantenergy is emitted per unit surface area (Watts/m2 ) from each ofthe two materials in the spectrum 0.4µm < λ< 0.8µm. Whichmaterial emits energy at the highest rate in this spectrum(assuming same surface area for both materials)?
