0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
What is the emissivity of black body?
Emissivity of the black body is 1. And this is probably the reason that the condenser of refrigerator is painted black to loose heat efficiently by radiation ,though there are other modes of heat transfer like conduction and convection which is not affected by colour of the body
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.
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.
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.
Is emissivity a property of a material?
Yes, emissivity is a material property that describes the ability of a material to emit thermal radiation. It is a dimensionless value between 0 and 1, with higher values indicating higher emissivity.
Why does black objects absorb more radiant heat than than chrome plated?
Black objects absorb more radiant heat than chrome plated objects because black objects have a higher emissivity value, which means they are better at absorbing and emitting thermal radiation. Chrome plated objects have a lower emissivity value, which means they reflect more radiation and absorb less heat.
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.
Can you have black skin on Animal Crossing?
No you can not get black skin
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 photo emissivity?
Emissivity of a surface is defined as its effectiveness in emitting thermal radiation. The term photo emissivity is likely used to narrow the focus to emitting visible light.
