What happens to a ray of light when it travels from one medium to another having equal refractive indices?

(a) What happens to a ray of light when it travels from one medium to another having equal refractive indices?
(b) State the cause of refraction of light.

(a) No refraction or bending would take place. The light will travel in a straight line.
(b) The refraction occurs due to change in speed of light as it enters from one medium to another.