Question
Define the terms:
(i) Absorptance,
(ii) Reflectance
(iii)Transmittance.
Solution
(i) Absorbtance: It is defined as the ratio of the amount of thermal radiation absorbed by the body in a certain time to the total amount of thermal radiation incident on it at the same time.
(ii) Reflectance: It is the ratio of the amount of thermal radiation reflected from a body in a certain time to the total amount of thermal radiation incident on it in the same time.
(iii) Transmittance: It is the ratio of the thermal radiation transmitted by it in a certain time to the total amount of thermal radiation incident on it in the same time.
