Question

State the rules used for drawing images formed by lenses

Answer 1

A ray of light from the object parallel to the principal axis of a lens passes through the principal focus (of a convex lens) or appears to pass through the principal focus (of a concave lens) after refraction.

Rule 1 For Obtaining Images Formed By Spherical Lenses

A ray of light passing through the optical centre of a lens goes straight without any deviation after refraction.

Rule 2 For Obtaining Images Formed By Spherical Lenses

A ray of light passing through the principal focus (of a convex lens) or appearing to pass through the principal focus (of a concave lens) emerges parallel to the principal axis after refraction.

Rule 3 For Obtaining Images Formed By Spherical Lenses