The dotted line is the normal (perpendicular) to the surface. In refraction calculations, angles are always measured between rays and the normal. The change in direction of a ray depends on the ...

The change in direction of a beam of light as it travels from one material to another is called refraction. The normal is a construction line drawn at right angles to the surface of the glass block.

A refractive index of 2.42 indicates that diamond ... at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position of the image, its nature and size.