Question

What are the three convenient light rays used to obtain the image of any object placed in front of a lens? Explain your answer with a proper diagram.

Answer 1

Parallel Ray: A ray of light coming parallel to the principal axis passes through the principal focus (F₂) after refraction through a convex lens.

Optical Centre Ray: A ray of light passing through the optical centre (O) of the lens goes straight through without any deviation.

Focal Ray: A ray of light passing through the principal focus (F₁) before hitting the lens emerges parallel to the principal axis after refraction.