A tungsten filament in a laboratory furnace behaves approximately like a perfect blackbody

PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter

Problem

A tungsten filament in a laboratory furnace behaves approximately like a perfect blackbody. At a certain setting the observed peak of its emission spectrum occurs at 580 nm. (i) Calculate the absolute temperature of the filament. (Take b=2.9×10−3 m Kb = 2.9 \times 10^{-3}\,\text{m\,K}.) (ii) Using your result from part (i), compute the radiant power emitted per unit surface area of the filament. (Use σ=5.67×10−8 W m−2K−4\sigma = 5.67 \times 10^{-8}\,\text{W\,m}^{-2}\text{K}^{-4}.) (iii) If the filament temperature is raised until the peak of the spectrum shifts to 450 nm, determine the factor by which the total radiant power per unit area increases.

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