Question

Draw a ray diagram to show the path of the refracted ray in each of the following cases:
A ray of light incident on a concave lens
1. parallel to its principal axis,
2. directed towards its principal focus.

Answer 1

In the case of a concave lens:
1. A ray parallel to the principal axis will diverge after refraction, and if extended backward, it appears to originate from the focal point.
2. A ray directed towards the focal point will refract and travel parallel to the principal axis after passing through the lens.
Both rays undergo refraction as per the laws of refraction, and their directions are governed by the shape and focal length of the concave lens.