what is the easiest way to draw convex and concave lenses correctly?

Asked by smitpranami | 26th Oct, 2015, 10:35: AM

Expert Answer:

  • There are certain rules to draw a ray diagram to locate the image formed by a spherical lens.
  • First rule: A ray of light parallel to the principal axis, after refraction from a convex lens, passes through the principal focus on the other side of the lens. In case of a concave lens, the ray appears to diverge from the principal focus on the same side of the lens.

  • Second rule: A ray of light passing through a principal focus, after refraction from a convex lens, emerges parallel to the principal axis. Whereas a ray of light appearing to meet at the principal focus of a concave lens after refraction emerges parallel to the principal axis.

  • Third rule: A ray of light passing through the optical centre of the lens emerges without any deviation.

 

Answered by Priyanka Kumbhar | 26th Oct, 2015, 04:22: PM