Using the formula n = 1/sin c, the higher the n , the smaller the c . With smaller c , total internal reflection can occur over a wider range of angle of incidences . i.e. the optical fibre can bend more and total internal reflection can still occur.

There are two main types of balancing toys. Type 01: CG below the pivot point Type 02: CG above the pivot

This video goes through the basic concepts that is required for moment questions. Go through the whole video to have know the different types of questions.