Question:
A $100 \mathrm{~W}$ bulb has tungsten filament of length $1.0 \mathrm{~m}$ and radius $4 \times 10^{-5} \mathrm{~m}$. The emissivity of the filament is $0.8$ and $\sigma=6.0 \times 10^{-8} W / m^{2}-K^{4}$. Calculate the temperature of the filament when the bulb is operating at correct wattage.
Solution:
