Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be_________________?
Correct answer: B
Explanation
The energy balance equation relates incident, reflected, transmitted, and emitted energy. Using the given values leads to an emissivity of 0.45.