What will be the surface area of a filament of 200 W incandescent lamp at 2000 K. `sigma = 5.67 xx 10^(-8) Wm^(-2) K^(-4)` and emissivity e = 0.3?

Explanation

To find the surface area of the filament of a 200 W incandescent lamp at a temperature of 2000 K, we can use Stefan-Boltzmann's law, which relates the power radiated by a black body to its temperature and surface area. The formula we will use is:

\[ P = e \cdot A \cdot \sigma \cdot T^4 \]

Where:
- \( P \) is the power (in watts),
- \( e \) is the emissivity (dimensionless),
- \( A \) is the surface area (in square meters),
...