Question

defined coefficient of emission​

Answer 1

Answer:

Einstein coefficients are mathematical quantities which are a measure of the probability of absorption or emission of light by an atom or molecule.

The Einstein A coefficient is related to the rate of spontaneous emission of light, and the Einstein B coefficients are related to the absorption and stimulated emission of light.

Explanation:

Answer 2

Answer:

(1) Emissive power or radiant power of a body (symn-

bol, R): The emissive power or radiant power of a

body at a given temperature is defined as the

quantity of radiant energy emitted by the body per

unit time per unit surlace area of the body at that

temperature.

(2) Coefficient of emission (or emissivity) of a body

(symbol, e): The coefficient of emission (or

emissivity) of a body is defined as the ratio of the

emissive power of the body (R) to the emissive

power of a perfect blackbody (R,) at the same

temperature as that of the body.