Prakash urja kyon le jata hai?

Prakash electromagnetic wave hota hai, jo photon naam ke kanno (particles) se bana hota hai. Har photon ek energy packet ki tarah kaam karta hai.

Photon ki energy Planck’s equation se di ja sakti hai:

E=hν

Yahan,

• E = photon ki energy
• h = Planck’s constant (6.626×10−34Js
• ν (nu) = prakash ki frequency (light wave ki tarang aavritti)

Kyon le jata hai prakash urja?

1. Photon ek energy carrier hota hai:
   • Prakash (light) sirf roshni ka madhyam hi nahi, balki energy bhi carry karta hai.
   • Jab ek electron ya atom excited state se ground state me aata hai, to excess energy photon ke roop me nikalti hai.
2. Prakash aur urja sambandhit hote hain:
   • Jab prakash kisi vastu par girta hai (jaise solar panel ya patte me photosynthesis), to photons apni energy transfer kar dete hain.
   • Solar energy me bhi yahi concept kaam karta hai.
3. Relativity ke anusar photon ka mass nahi hota, par uska momentum hota hai:
   • Albert Einstein ke special relativity ke anusar, photon ka rest mass zero hota hai, lekin uska momentum hota hai.
   • Photon ka momentum: p=hλp = \frac{h}{\lambda} (jahaan λ (lambda) wavelength hoti hai)
4. Photoelectric aur Compton effect se energy transfer proof hota hai:
   • Photoelectric effect me prakash kisi dhatu (metal) se electron nikal sakta hai.
   • Compton effect me photon kisi electron se takrakar apni energy aur momentum transfer kar sakta hai.

Nishkarsh:

Prakash energy isliye le jata hai kyunki uske photons me fixed quantum energy hoti hai, jo kisi vastu ya electron me transfer ho sakti hai. Ye energy uski frequency aur wavelength par depend karti hai.