Question

Define second focus and second focal length of a lens, also draw a ray diagram

for convex lens if a body is placed at 2F1.​

Answer 1

Answer:

Concave lens representing second focus as F 2

The second focal point for a concave lens is a point F 2

on the principal axis of the lens such that the rays of light incident parallel to the principal axis,

after refraction from the lens, appear to be diverging from this point.