Black Body Radiation: Will it Behave as Perfect Black Body?

In summary, the conversation discusses the behavior of a body with given emissivity inside a perfect black body. There is a question about whether or not the body will start behaving like a perfect black body, and the speaker asks for clarification on whether they are looking at the black body from the outside or the behavior of the body inside. The conversation also mentions coating a normal ball with lamp black and whether it will behave like a black body. Ultimately, the conversation concludes that a black body absorbs all radiations and the coated ball should behave like a black body.
  • #1
Abhisuma
6
0
Will a body of given emissivity kept inside a perfect black body start behaving as a perfect black body?
 
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  • #2
Why should it?
 
  • #3
DrClaude said:
Why should it?

I meant the whole system black body having a normal body inside it
 
  • #4
Are you looking at the blackbody from the outside, or are you interested in the behavior of the grey body inside?
 
  • #5
DrClaude said:
Are you looking at the blackbody from the outside, or are you interested in the behavior of the grey body inside?
Can you please answer it for both
 
  • #6
What do you think?
 
  • #7
DrClaude said:
What do you think?
I am actually confused.The actual question that my teacher asked was that if I coat a normal ball with lamp black will it start behaving as a perfect black body
 
  • #8
Abhisuma said:
I am actually confused.The actual question that my teacher asked was that if I coat a normal ball with lamp black will it start behaving as a perfect black body
Then go back to the definition of a black body, and think what happens if you look at the painted ball from the outside. Does it behave like a blackbody?
 
  • #9
DrClaude said:
Then go back to the definition of a black body, and think what happens if you look at the painted ball from the outside. Does it behave like a blackbody?
A black body is the body that absorbs all radiations falling on it so when a electomagnetic radiation is directed towards the ball the lamp black will absorb it so the ball must behave like a black body.
Am I correct?
 
  • #10
Abhisuma said:
A black body is the body that absorbs all radiations falling on it so when a electomagnetic radiation is directed towards the ball the lamp black will absorb it so the ball must behave like a black body.
Am I correct?
Yes.
 
  • #11
DrClaude said:
Yes.
Thanks a lot!
 

FAQ: Black Body Radiation: Will it Behave as Perfect Black Body?

1. What is black body radiation?

Black body radiation refers to the electromagnetic radiation emitted from a black body, which is an idealized object that absorbs and emits all radiation that falls on it. It is a fundamental concept in thermal physics and plays a crucial role in understanding the behavior of objects at high temperatures.

2. How does a black body behave as a perfect black body?

A perfect black body is an object that absorbs all radiation that falls on it, without reflecting or transmitting any of it. This means that it also emits radiation at all wavelengths and temperatures, making it a perfect emitter. In other words, a black body behaves as a perfect black body by absorbing and emitting radiation at all wavelengths and temperatures.

3. Does every object behave as a perfect black body?

No, not every object behaves as a perfect black body. In fact, most objects are not perfect emitters and absorbers of radiation. Real-world objects reflect, transmit, and absorb different amounts of radiation depending on their material and surface properties. However, certain objects, such as stars and planets, can be approximated as black bodies due to their high temperatures and the nature of their radiation.

4. Why is black body radiation important in science?

Black body radiation is crucial in science because it helps us understand the behavior of objects at high temperatures, such as stars and planets. It also plays a significant role in fields such as thermodynamics, astrophysics, and quantum mechanics. Additionally, black body radiation is used in many practical applications, including infrared cameras and thermal imaging devices.

5. Is it possible to achieve perfect black body behavior in real-world objects?

No, it is not possible to achieve perfect black body behavior in real-world objects. This is because perfect black body behavior requires an object to both absorb and emit radiation at all wavelengths and temperatures, which is not possible in reality. However, scientists can use techniques such as coating an object with a material that absorbs all radiation to approximate perfect black body behavior.

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