An indirectly heated filament is radiating maximum energy of wavelength `2.16xx10^-5cm`. Find the net amount of heat energy lost per second per unit area, the temperature of the surrounding air is `13^@C`. Given `b=0.288cm-K.sigma=5.77xx10^-5erg//s-cm^(2)-K^(4)`).

Explanation

To solve the problem of finding the net amount of heat energy lost per second per unit area from the indirectly heated filament, we will follow these steps:

### Step 1: Apply Wien's Displacement Law
Wien's Displacement Law states that the wavelength at which the emission of radiation is maximum (λm) is inversely proportional to the absolute temperature (T) of the black body. The formula is given by:

\[ \lambda_m \cdot T = b \]
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