ICSE Class 8 Answered
Define principal focus in terms of convex as well as concave lens.
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
Expert Answer
Principal focus of a convex lens: The rays of light incident parallel to principal axis meet after refraction at a point on the other side of the lens on the principal axis. This point is called principal focus.
Principal focus of a concave lens: The rays of light incident parallel to principal axis appear to diverge after refraction from a point on the same side of the lens on the principal axis. This point is called principal focus.
Answered by | 04 Jun, 2014, 03:23: PM
