Guest question from Satya Saha.

What principle is depicted here?

Cracked by: raklodramA , rohanquizzer , Raghuvansh , shrik , Rogi , Siddarth Pai , S M MUNEER ALI , dineshk , Sumanth Patlolla , Ananth , KK , jowens , udupendra , Dibyo , Manish Achuth , abinash sharma , Thejas V R , Shwetha Maiya and krudebox

Answer:
Quoting wikipedia – “Reproduction of a page of Ibn Sahl’s manuscript showing his discovery of the law of refraction, now known as Snell’s law.”