A convex lens of focal length 20cm

Question:

A convex lens of focal length $20 \mathrm{~cm}$ and a concave lens of focal length $10 \mathrm{~cm}$ are placed $10 \mathrm{~cm}$ apart with their principal axis coinciding. A beam of light travelling parallel to the principal axis and having a beam diameter $5 \mathrm{~mm}$, is incident on the combination. Show that the emergent beam is parallel to the incident one. Find the beam diameter of the emergent beam.

Solution:

Leave a comment

Close

Click here to get exam-ready with eSaral

For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.

Download Now