RRB NTPC Mains or Stage 2 Model Paper 1 with solutions

(3) Refraction is the bending of the path of a light wave as it passes across the boundary separating two media.Light refracts whenever it travels at anangle into a substance with a different refractive index. This change of direction is caused by a change in speed. For example,when light travels from air into water, it bends and travels at a different angle or direction.