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Do different objects at same temperature emits different amounts of radiation?
Yes, different objects at the same temperature can emit different amounts of radiation depending on their emissivity. Emissivity is a material-specific property that determines how efficiently an object emits thermal radiation. Objects with higher emissivity values will emit more radiation at a given temperature compared to objects with lower emissivity values.
What is the emissivity of an ideal reflector?
The emissivity of an ideal reflector is 0, meaning it reflects all incoming radiation without emitting any.
Do dull silver surfaces emit the same amount of radiation as shiny white surfaces?
Yes, dull silver surfaces and shiny white surfaces will emit similar amounts of radiation. The color or shininess of a surface does not affect its ability to emit radiation; rather, it is determined by the material and temperature of the surface.
How does a silver surface work in radiation?
A silver surface can reflect and scatter radiation due to its high reflectivity and smooth surface. This property allows silver to effectively redirect or absorb radiation that comes into contact with it, making it useful in various applications such as in mirrors or radiation shielding.
What is a physical property is shown by scratching one material with another?
A physical property shown by scratching one material with another is hardness. This property refers to a material's ability to resist scratching or indentation by another material. By scratching one material with another, you can gauge which material is harder based on the scratch resistance.
Do different objects at same temperature emits different amounts of radiation?
Yes, different objects at the same temperature can emit different amounts of radiation depending on their emissivity. Emissivity is a material-specific property that determines how efficiently an object emits thermal radiation. Objects with higher emissivity values will emit more radiation at a given temperature compared to objects with lower emissivity values.
What is emission?
a type of nebula
A material with zero emissivity radiates to other body in vacuum or not?
Zero emissivity means generally no radiation for the far-field. However, for the near-field case, energy may flow to another bodies.
What is the definition of 'emissivity'?
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.
What influences radiational cooling?
Properties of the material such as thermal conductivity, specific heat, and emissivity, and the temperature of the surroundings.
Why heat sinks are black anodized?
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.
Do reflector panels have high or low emissivity?
low emissivity
What is the emissivity of an ideal reflector?
The emissivity of an ideal reflector is 0, meaning it reflects all incoming radiation without emitting any.
What is the emissivity of silicon?
The emissivity of silicon can vary depending on the specific type of silicon (e.g., monocrystalline, polycrystalline) and surface condition. However, typically, the emissivity of silicon is around 0.65-0.75 in the infrared spectrum.
Do dull silver surfaces emit the same amount of radiation as shiny white surfaces?
Yes, dull silver surfaces and shiny white surfaces will emit similar amounts of radiation. The color or shininess of a surface does not affect its ability to emit radiation; rather, it is determined by the material and temperature of the surface.
How does a silver surface work in radiation?
A silver surface can reflect and scatter radiation due to its high reflectivity and smooth surface. This property allows silver to effectively redirect or absorb radiation that comes into contact with it, making it useful in various applications such as in mirrors or radiation shielding.
What is the definition of property in scientific terms?
characteristic or functionality of a material = property of a material
