i have a doubt...plz help.....?

Question

i have come 2 know that when energy is supplied to a black body,it absorbs all radiations and emits a continous spectrum...now,when a bar of iron is heated,it turns red to blue...how does this happen......so,how is the temperature related to the colour..........and what is the differnce if the energy is in the form of heat....and when in form of light?????

Answer 1

Wien's Law

Wavelength is inversely proportional to temp. This means that the more you heat an object, the light emitted by it shifts towards the blue end of the spectrum.

The only difference is that when it is emitted as light, the photons fall in the visible range.

Answer 2

Well, first let's start of by saying that Infra Red waves are heat. That is what you feel when you are not touching something but it you can still feel the warmth. IR is part of the energy spectrum. IR rays have a longer wavelength than visible light, and so we know that they have a lower energy than visible light (Energy=speed of light/wavelength). So, if you give the IR radiation more energy, the wavelength will get shorter. First it will turn red (because that is the longest wavelength of visible light). It will be blue last because blue has a shorter wavelength than red, and thus a higher amount of energy. Temperature is related to the amount of energy, and so if an object has a higher temperature, it has more energy.

So the only difference in heat and light is the amount of energy they have, and (as a result of energy) have different wavelengths.

I hope this helped!

Answer 3

E=hv, where E is the energy , h blanck constant , v(not v but neo is the frequency, wave length =1/v
so, E=h/v , in other word the wavelength inversely proportional with energy, the lowest wavelength the higher energy, the color changed according to energy gained or lost,
photon emission when the energy in a form of light, heat radiation when the energy is a heat.

Answer 4

Infrared rays.