Physics
Answer
A plane normal to the principal axis, passing through the focus, is called the focal plane of a lens.
A lens has two focal plane.
(a) A plane passing through the first focal point and normal to the principal axis of the lens is called the first focal plane.
(a) A plane passing through the second focal point and normal to the principal axis of the lens is called the second focal plane.
Related Questions
State the condition when a lens is called equiconvex or equi-concave.
Define the term focal length of a lens.
State the condition for each of the following :
(a) a lens has both its focal lengths equal.
(b) a ray passes undeviated through the lens.
Complete the following sentence:
If half part of a convex lens is covered, the focal length …….. change, but the intensity of image ………