Define: i. Transmissivity ii. Black body iii. Grey body iv. Reflectivity

Define: i. Transmissivity ii. Black body iii. Grey body iv. Reflectivity
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1 Answer

Answer :

Transmissivity:

It is the the fraction of energy which is transmitted through the body.

Or

The ratio of amount of energy transmitted to the amount of energy incident on a body.

Black body: A black body is an object that absorbs all the radiant energy reaching its surface from all the direction with all the wavelengths. Gray body:

Grey Body: A gray body is defined as a body whose absorptivity of a surface does not vary with variation in temperature and wavelength of the incident radiation. It absorbs a  definite percentage of incident energy irrespective of wavelength. Its absorptivity lies between 0 to 1.

Reflectivity:

It is defined as the ratio of amount of energy reflected to the amount of energy incident on a body.
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