7) Why does total internal reflection happen? Why can\'t fiber optic cables be bent beyond 90 degrees? Solution when a light passes from a medium of one refractive index to another medium with a lower refractive index it bends or refracts away from the line perpendicular to the surface. at a perticular angle light canot go to the another medium such an angle is called as critical angle from snells law sin(crtical angle) = n2/n1 the critical angle is the angle of incident ray which causes the refracted ray to bend the angle of 90 degrees. there fore any angle of incidence beyond the critical angle means that the light ray is going to bend inwards. this is the internal reflection. .

1. 7) Why does total internal reflection happen? Why can't fiber optic cables be bent beyond 90
degrees?
Solution
when a light passes from a medium of one refractive index to another medium with a lower
refractive index it bends or refracts away from the line perpendicular to the surface.
at a perticular angle light canot go to the another medium
such an angle is called as critical angle
from snells law
sin(crtical angle) = n2/n1
the critical angle is the angle of incident ray which causes the refracted ray to bend the angle of
90 degrees. there fore any angle of incidence beyond the critical angle means that the light ray is
going to bend inwards. this is the internal reflection.