Write about the behaviour of light rays when they incident on a lens

  1. Situation -1: Ray passing through the principal axis => It is not deviated.

  1. Situation - II : Ray passing through the pole =» It is also undeviated

  1. Situation - III: Rays travelling parallel to the principal axis => They are converge at focus or diverge from the focus.

  1. Situation - IV : Ray passing through focus => It will take a path parallel to principal axis after refraction.

  1. Situation-V: Parallel rays fall on a lens making some angle with principal axis. => They converge at a point or diverge from a point lying on a focal plane.