Question

The distance between the potical centre
and point of convergence is called focal
length in which of the following cases?
answer with explanation ​

Answer 1

Answer:

That is why, a lens has two foci. They are at equal distance from the optical centre. Focal length of a convex lens: The distance between the optical centre and principal focus of a lens is called focal length. Focal length of a lens depends on the refractive index of the glass and its curvature.

Explanation:

hope u have been understood thanku