The emissivity is 0...
Dull silver surfaces and shiny white surfaces can have different emissivity values, which means they might not emit the same amount of thermal radiation. Emissivity is a property that quantifies how effectively an object emits thermal radiation compared to a perfect blackbody at the same temperature. A blackbody has an emissivity of 1, and objects with emissivity closer to 1 are better emitters of thermal radiation. Dull surfaces, including dull silver surfaces, typically have higher emissivity compared to shiny surfaces. Shiny surfaces often have lower emissivity because their smooth and reflective nature reduces their ability to emit thermal radiation effectively. White surfaces can vary in terms of their shininess and emissivity. A shiny white surface might have a lower emissivity, while a more matte or dull white surface may have a higher emissivity. Therefore, if the dull silver surface has a higher emissivity compared to the shiny white surface, it will emit more thermal radiation than the shiny white surface at the same temperature. However, it's important to note that the exact emissivity values can vary based on the specific properties and conditions of the surfaces, so it's best to refer to specific emissivity measurements for accurate comparisons.
The concept involved here is Emissivity - the ability to emit energy. e is the usual symbol, and a perfect emitter would have an e of 1. Your perfect black body will have this emissivity of 1.A highly polished surface (polished at all the wavelengths concerned) will have an emissivity much smaller. Polished silver has an emissivity of about 0.02.In general the emissivity of a surface is inversely related to its reflectance, but this does vary with the surface finish, colour, and the mass of the object.It is worth noting, that low emissivity glass is used with effect in the double glazing of windows.
Rigidity is a property of material itself whereas stiffness is a function of material property, sectional property and end conditions.
Yes, in principle, but only if their emissivity is independent of temperature. Generally, emissivity is a very weak function of temperature.
a type of nebula
Zero emissivity means generally no radiation for the far-field. However, for the near-field case, energy may flow to another bodies.
The term "emissivity" refers to the relative power of a surface to emit heat by radiation. It could also be defined as the ratio of energy radiated by a particular material to energy radiated by a black body.
the emissivity of Si is 0.6
The emissivity is 0...
Properties of the material such as thermal conductivity, specific heat, and emissivity, and the temperature of the surroundings.
Radiative heat transfer (heat transfer by electromagnetic radiation) is proportional to e*(T1^4 - T2^4) where T1 is the absolute temperature of the material, T2 is the absolute temperature of the surroundings, and e is the emissivity coefficient. A black material has a high emissivity coefficient, while a silvery material has a low emissivity coefficient. However, the emissivity coefficient cuts both ways, so to speak. A black material in thermodynamic equilibrium with its environment absorbs more radiation, true. But it also emits more radiation (this is necessary for equilibrium to hold). Likewise, a silvery material absorbs less radiation, and also emits less radiation. Conductive heat transfer ensures that the black material on the surface of the heat sink remains hot. The surroundings are at a lower temperature. Therefore T1 and T2 are set, and the heat transferred from the heat sink to the surroundings is simply proportional to e, the emissivity coefficient.
low emissivity
Dull silver surfaces and shiny white surfaces can have different emissivity values, which means they might not emit the same amount of thermal radiation. Emissivity is a property that quantifies how effectively an object emits thermal radiation compared to a perfect blackbody at the same temperature. A blackbody has an emissivity of 1, and objects with emissivity closer to 1 are better emitters of thermal radiation. Dull surfaces, including dull silver surfaces, typically have higher emissivity compared to shiny surfaces. Shiny surfaces often have lower emissivity because their smooth and reflective nature reduces their ability to emit thermal radiation effectively. White surfaces can vary in terms of their shininess and emissivity. A shiny white surface might have a lower emissivity, while a more matte or dull white surface may have a higher emissivity. Therefore, if the dull silver surface has a higher emissivity compared to the shiny white surface, it will emit more thermal radiation than the shiny white surface at the same temperature. However, it's important to note that the exact emissivity values can vary based on the specific properties and conditions of the surfaces, so it's best to refer to specific emissivity measurements for accurate comparisons.
characteristic or functionality of a material = property of a material
The concept involved here is Emissivity - the ability to emit energy. e is the usual symbol, and a perfect emitter would have an e of 1. Your perfect black body will have this emissivity of 1.A highly polished surface (polished at all the wavelengths concerned) will have an emissivity much smaller. Polished silver has an emissivity of about 0.02.In general the emissivity of a surface is inversely related to its reflectance, but this does vary with the surface finish, colour, and the mass of the object.It is worth noting, that low emissivity glass is used with effect in the double glazing of windows.
It will be crystal.Crystal is the main property