Difference between a blackbody and a gray body

1. Difference between a blackbody and a gray body Blackbody Gray body 01 Its surface absorptivity is independent of incident light wavelength and temperature conditions. And it absorbs some fraction of incident light that falls on its surface. It absorbs incident light of all wavelengths falling on its surface at a constant temperature. It is an imaginary ideal body. It is an actual physical body. 02 The absorptivity of a blackbody is one. Ans its reflecting and transmitting powers are zero. Its absorptivity varies between 0 and 1. And it has definite reflective and transmitting powers depending upon the nature of the substance. 03 The energy density of emitted radiations by a gray body depends upon its nature, size, shape, and composition. The energy density of radiations emitted by a blackbody is independent of its nature, size, and shape. Instead, it depends only on temperature conditions. The blackbody radiation is isotropic in nature. The gray body radiations are anisotropic in nature. 04 The emissivity of a blackbody is one. The emissivity of the gray body varies between 0 and 1. 05 At a particular wavelength and in thermal equilibrium conditions, the emissive power of a gray body is the product of its absorbing power and the blackbody's emissive power at that wavelength. The blackbody's emissive power is a universal constant at each wavelength in the thermodynamic equilibrium state.