Question

Glas ka apvartnank 1/2 hai air me prakash ki Chal 300000000hai to glass me prakash ki Chal Kiya hi hi?

Answer 1

ग्लास मे प्रकाश की चाल आधी होगी
अगर हवा में 3x10^8 तो ग्लास में 1.5x10^8 हो जाएगी

This is a question from the speed of light segment and can be easily solved by understanding of the refractive indices of materials.
It is Given that the ref. of glass is 1/2 henceforth the speed of light in glass must be 1/2 the speed of light in vacuum hence
The speed of light in glass is 1.5x10^8 m/s
Hope it helps :)