core aur claddiing aik material ka bane hote ha lakin impurities ke waja se dono material same nahi rehte yani 100% pure nahi hote .in impurities ke waja se inka refractive index change ho jate ha

aksar manufacturers aik khas refractive index (n) hasil karne kaliye kuch impurities shamil kar dete ha.

fibre ma light signal jis osool per travelling karta ha us ko total internal reflection(TIR) kehte ha.total internal reflection kia hote ha?

yaha per 2 cheze samajhne ke ha

1 Reflection
2 Refraction

1 Reflection : jab koi ray/beam/light/signal kesi chez (boundry) se taqra ke puri ka pori wapas ajate ha is ko reflection bolte ha. jo ray taqrane kalye ja rahe ha is ko incident ray bolte ha aur jo taqra ka wapas ajate ha is ko reflected ray bolte ha.
incident ray jo angle banata ha isko incident angle bolte ha aur reflected ray jo angle banata ha is ko reflected angle bolte ha.
NOTE : incident angle = reflected angle (for reflection)
@1 = @3 ; @ = angle
example :mirror (aiyna) suraj ka light ko reflect karta ha

2 Refraction: jab koi ray kesi chez se taqrane ka bad kuch to wapas ate ha aur kuch use medium ma chale jate ha to is ko refraction bolte ha.yani refraction ma 2 chezen hoti ha
kuch kight wapas ate ha aur kuch usi taqar wale chez ka andar chale jate ha
to aksar chezo ma refraction he hote ha . lakin mirror wagira jaise chezo ma reflection hote ha
total internal reflection ma refraction nahi hone dia jata balke is ma incident angle ko aisa set kia jata ha ta ke sare light wapas reflect ho sake. jis angle per refracted angle 90 degree kabarabr ho jaye ga (with respect to normal) isko critical incident angle bolte ha.is angle per (refracted part) light na material ka andar ja rahe hote ha na wapas arahe hote ha balke material ka sarface ka sath he guzar jate ha. note reflected part reflect ho raha hota ha.

is kaliye snells law use hota ha ka incident angle kitan rake ka TIR hasil ho

n1.sin@1 = n2.sin@2 ; @1= incident angle; @2 refracted angle


ab agar critical angle se ham incident angle increase karenge to light totally reflect hoge wapas medium ma aur ise ko total interna reflection bolte ha.

jaha per samaj na aye poch liya kare

QUESTIONS FOR YOU:
1 RERACTION MA JO PART REFLECT HOTE HA KAI USKA ANGLE BE INCIDENT ANGLE KABARABR HOTA HA ????
2 US ANGLE KO KIA BOLTE HA JIS PER TIR(TOTAL INTERNAL REFLECTION ) HOTE HA ???