Question 12.7: 100 W of radiant energy leave a frosted glass spherical ligh...

Thermal Radiation Heat Transfer

100 W of radiant energy leave a frosted glass spherical light bulb 10 cm in diameter enclosed in a fixture having a flat glass plate as in Figure 12.2. If the glass is 2 cm thick and has a gray extinction coefficient of 0.05 $cm^{−1},$ find the intensity directly from a location on the bulb surface leaving the fixture at an angle of θ = 60° as shown in the figure. Neglect interface-interaction effects resulting from the difference in refractive index between the glass and surrounding air; these effects are included in Chapter 17.

12.2

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