Three ideal blackbodies are heated to different steady temperatures
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Modern Physics · Modern Physics
Problem
Three ideal blackbodies are heated to different steady temperatures. Their spectral intensity distributions are described below:
• Spectrum A attains its maximum intensity at a wavelength of 650 nm.
• Spectrum B attains its maximum intensity at a wavelength of 520 nm.
• Spectrum C attains its maximum intensity at a wavelength of 430 nm.
Answer the following questions related to these spectra.
(i) Arrange the three spectra in ascending order of their absolute temperatures.
(ii) Identify which spectrum corresponds to the hottest blackbody and justify your answer on the basis of an appropriate physical law.
(iii) Explain how the observed colour of the radiating surface would qualitatively change as the temperature increases from the level of spectrum A to that of spectrum C.
(iv) State whether the total radiant power per unit area increases or decreases as one moves from spectrum A to spectrum C and explain your reasoning.