The filament of a tungsten lamp has an operating temperature of 3000 K and an emissivity of 0.24. The radius of the filament is 0.4 mm and the power of the lamp is 135 watts. What is the length of the filament?<br />(Stefan-Boltzmann constant = 5.67x10⁸ W/m²K⁴)<br /><br />Watch videos related to MODERN PHYSICS:<br />https://dailymotion.com/playlist/x90qrm<br /><br />#modernphysics
