Modern Physics

Cool goIITian

Joined: 2 Jul 2009
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26 Aug 2011 11:46:33 IST
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well.. this question  may seem to be foolish to many but its still confusing me

acc to planck energy of photon is quantised and E=hv(new) this is in respect to particle nature of light..i want to know that in this case we have used frequency on the right side..its a character of wave and we have used it in the exp to justify particle nature of light..this seems to be a contradiction to me...

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New kid on the Block

Joined: 24 Aug 2011
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26 Aug 2011 17:33:05 IST
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This question's answer lies in the question..When you say that energy is quantised it means that energy is in pieces or packets or u can easily call it photon, and this quantisation is in so small-small -small that it almost behave like a wave.U can see from de broglies thoughts tht every particle has also some momentum,But he has also told that this valid only for very high speed or very small particle, so that the wavelenth that comes is considerable.And if he tells this he doesnt meen that a 1 kg ball does not have wavelenth, it has but its small enough to neglect.
Yagyadutt Mishra's Avatar

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Joined: 19 Feb 2009
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26 Aug 2011 18:08:23 IST
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Just a rough picture to show ...and proof that light is nothing but a wave carrying out infinte number of photons with it !
Carrying photons means ....light carry out its energy by packing it in photons ..!

(Just for fun ..when u go out on journey ...u pack your clothes in boxes ..That is what quantisation means ..! If each box has 10 clothes and you have arround 4 boxes...then total clothe u have is 40 ..!)

Similary Every light wave travels in a straight line with its energy packed in photons...! Number of photons determing how intense the light is ..!

Laser has very high intensity ..Means laser carry out large number of photons with  ..
Theory of Quantization says that ...Every wave has its energy quantized ..! Obviously In case of light what it is ??
Total sum of energy carried out by photons..!

If we have n photons energy will be nhv ..! Where v is the frequency of the wave ..!
Now your point is that v is related to wave nature ...then why it determines the enrgy of photon which is of a particle nature ...

Answer is that ...the wave is nothing but collections of discussed ..So Energy of wave will be equally divided and distributed in the photons ..!

Quantum theory basically relate the wave nature with the particle nature :) ....So energy of wave can be given as total energy of photon....and one photon's energy can be determined by the wave's energy !
Ask your doubts further...!

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