Question

When a ray of light passes from a rarer to denser medium it bends towards the normal. (True=1 or false=0).

Answer 1

Laws of refraction;-

1. The incident ray,the refracted ray and the normal to the refracting surface at the point of incidence lie in the same plane.
2. For a given pair of media and for a given colour of light the ration between the sine of angle of incidence to the sine of refraction is a constant.This constant is known as refractive index of the second medium with respect to the first medium.

When a ray of light passes through a glass slab, $\angle i,\angle r$ and the normal all lie in the same plane.
When a ray of light passes from one medium to another, here from air to glass or glass to air, the ratio $\frac{sini}{sinr}=constant$.