Radiation: the Filament in a Light Bulb Has a Diameter

Multiple Choice

Radiation: The filament in a light bulb has a diameter of 0.050 mm and an emissivity of 1.0. The temperature of the filament is 3000°C. What should be the length of the filament so it will radiate 60 W of power? The Stefan-Boltzmann constant is 5.670 × 10^-8 W/m² · K⁴.

A) 11 cm
B) 9.4 cm
C) 8.6 cm
D) 7.2 cm
E) 5.9 cm