(Solution Download) A tungsten light filament operates at a temperature of 3400 K. What fraction of the radiation lies..

A tungsten light filament operates at a temperature of 3400 K. What fraction of the radiation lies in the visible range, 0.4 to 0.7 µm? Suppose the tungsten light filament in Problem 8-131 consumes 400 W of electric power and all the visible light is transmitted through the enclosing glass bulb. Calculate the area of the filament to dissipate the total of 400Wof radiant energy. What is the efficiency of the lightbulb?