Prakash ka dhruvan kya hota hai? Pravartan ke dvara dhruvan.

Friends jaise hi ham class 12th me jate hain to hame pata chalta hai ki optics chapter 12th physics ka ek important chapter hai aur iska 2 part hai. Pahla part hai ray optics aur dusra part hai wave optics. Wave optics me ek important chapter hai jiska name hai polarization of light. Isi polarization of light ko prakash ka dhruvan bhi kahte hain. To friends aaj ham prakash ke dhruvan ke bare me deatil janege ki prakash ka dhruvan kya hota hai. Prakash ka dhruvan kise kahte hai. 

Prakash ka dhruvan kya hai

Friends ham sabhi ko pata hai ki light ek electromagnetic wave hai aur jab light chalti hai to uske charo or electric field aur magnetic field dono rahtee hai. Electric field aur magnetic field dono light ke around apne-apne direction me vibrate karti hai. To jis light me electric field aur magnetic field apne-apne direction me vibrate kartee hai aur agar electric field ke vibration ka direction arbitrary charo direction me ho to us tarah ke light ko un polarized light kahte hain. Non-Polarized light ka electric field charo direction me vibrate karti hai. To ab aap non-polarized light ke bare me acchi tarah se samajh gaye honge. Ab ham polarized light ke bare me janege.

Ab aap itna to jaan hi gaye ki light jab chalta hai to electric field uske charo or vibrate kartee hai. Lekin is light ko ek special method se aisa banaya jata hai jis se uska electric field only ek fixed direction me ya ek fixed plane me vibrate kartee hai to us tarah ke light ko ham polarized light kahte hain. Polarized light ya dhruvit prakash me light ke electric field ka vibration ek fixed direction me hota hai. 

Light ko polarized banane ke lie light ko polaroids ya polarizer se pass karbate hai. Jab light ko polariser se pass karbaya jata hai to light polarized ho jata hai kyonki polaroids se pass karne ke baad light ka electric field ek fixed plane me vibrate karne lagta hai. Polaroid ka use bahut sare devices me hota hai, jaha bhi light ke polarization ki baat aati hai bha par polaroid ka name jarur aata hai. Polaroid aise material ka bana hota hai jis se jab light pass kartee hai to apne aap light ke pass karne ke baad light ka electric field ek fixed plane me vibrate karne par majbur ho jati hai. Jab light ka electric field ek fixed plane me vibrate karne lagta hai to bah light polarized ho jata hai.

Light ke polarization ke baad light ka electric field jis plane me vibrate karta hai us plene ko plane of vibration kahte hai aur plane of vibration ke perpendicular plane ko plane of polarization kahte hain. Plane of polarization ke along electric field ka koi vibration nhi hota hai.

Prakash ke pravartan se dhruvan

Abhi hamne upar jana ki light ka polarization polaroids ke jariye kiya jata hai lekin light ka polarization naturally bhi hota hai. Jab light kisi transparent medium par incident kartee hai to jo light reflect karta hai ya jo light refract karta hai, dono ke dono light partially polarized ho jata hai. Matlab ki light ke reflection se bhi light ka partially polarization hota hai. Brewster name ke scientist ne yah pata lagaya ki jab light reflection se polarization hota hai to reflected light me polarization ka amount angle of incidence par depend karta hai. Harek transparent medium ke lie ek aisa angle jarur hota hai jis angle par agar light incident kre to reflected light fully polarized hota hai. Isi angle ko angle of polarization kahte hain. Jab koi light angle of polarization ke angle par incident karti hai to us time reflected light fully polarized ho jata hai.

Brewster law

Hamne upar jana ki angle of polarization ka value ke bare me sabse pahle Brewster name ke scientist ne bataya tha. Brewster ne bataya ki jab light angle of polarization par incident kartee hai to bah fully rup se polarized ho jati hai. 
Brewster law ke anusar angle of polarization ka tan value us transparent medium ke refractive index ke barabar hota hai.