1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Radiation of a body

  1. Jul 30, 2016 #1
    Guys I have little doubt and I want you to rectify that Am I wrong or right. I think any body at room temp or any temp emits each and every type of radiation but intensity of radiation is less for high wavelength or low wavelength waves at room temp and intensity is good enough for visible light. I am asking this on understanding of black body.
     
  2. jcsd
  3. Jul 30, 2016 #2
    Intensity usually comes to picture only when the body is not diffuse. In that case body will have different intensities in different directions. I think what you are talking about is the distribution of thermal radiations over the electromagnetic spectrum when the body is at constant temperature. Let us consider a diffuse body for simplicity. A body at a certain temperature emits radiation over a wide range of wavelengths. But there will be a certain wavelength about which the energy emitted per unit area of the emitting body is maximum. Now if you increase the temperature of the body this wavelength, about which energy emission is maximum, decreases. This shift in wavelength associated with maximum energy radiation with an increase in temperature is called Wein's Displacement.
     
  4. Jul 30, 2016 #3
    Yeah i know Wein's law of displacement..but I want to ask that suppose I have a cell phone in my hand so would a normal object like cell phone would emit all types of radiations?
     
  5. Jul 30, 2016 #4

    jbriggs444

    User Avatar
    Science Advisor

    Yes. Though the rate at which hard gammas are emitted will be exceedingly low.

    Google for Plank's law and the Ultraviolet Catastrophe.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Radiation of a body
  1. Black Body radiation (Replies: 1)

  2. Black body radiation (Replies: 4)

  3. Black-body Radiation (Replies: 3)

  4. Black body radiation (Replies: 15)

Loading...