PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
Three idealized continuous emission curves, labeled A, B, and C, are plotted on the same axes of spectral intensity (vertical axis) versus wavelength (horizontal axis, running from 200 nm to 1200 nm).
• Curve A reaches its maximum intensity at 300 nm.
• Curve B reaches its maximum intensity at 500 nm.
• Curve C reaches its maximum intensity at 1000 nm.
At every wavelength the intensity of curve A exceeds that of curve B, and the intensity of curve B exceeds that of curve C.
(a) Rank the surfaces that produced curves A, B, and C in order of decreasing temperature. Explain your reasoning based solely on the information provided by the graph.
(b) Identify which curve corresponds to the greatest total power emitted per unit surface area. Justify your answer by referring to specific graphical features.
(c) The surface responsible for curve B is known to be at a temperature of 5800K. Using the graph, estimate the temperature of the surface that produced curve A. Show your calculation steps and clearly state any approximations you make.
(d) An astronomer claims that curve C represents the spectrum of an object at 1500K. Evaluate whether this claim is consistent with the information given in the stimulus. Support your answer with quantitative or qualitative reasoning.