Question

A straight stick partly dipped in water obliquely ,appears to be bent at the surface of water

Answer 1

it's bcoz of refraction due to this it is bent the ray of light and when ray treval one medium to another medium.......!!!!
I hope it's helpful to you please mark as a brain list.......!!!!

Answer 2

THIS HAPPENS BECAUSE WHEN A RAY OF LIGHT GOES FROM ONE MEDIUM TO ANOTHER OF DIFFERENT DENSITY, IT BENDS . DUE TO THE BENDING, IT GIVES THE PRECEPTION AND THE PORTION OF STICK UNDER THE WATER IS RAISED AND BENT. SIMILARLY , WHEN YOU PLACE A COIN IN THE BEAKER IT SEEMS THAT THE COIN IS RAISED . THIS BENDING OR CHANGING IN DIRECTION OF LIGHT AS IT PASSES FROM ONE MEDIUM TO ANOTHER IT IS KNOWN AS REFRACTION OF LIGHT.

HOPE THIS ANSWER HELPS PLEASE MARK AS BRAINLIEST