Question

derive the lens maker formula

Answer 1

Derivation Of Lens Maker Formula. Lenses of different focal lengths are used for various optical instruments. The focal length of a lens depends upon the refractive index of the material of the lens and the radii of curvatures of the two surfaces.

Answer 2

Answer:

I've already answered this, so repeating the same.

In optics, the relationship between the distance of an image (v), the distance of an object (u) and the focal length (f) of the lens is given by the formula known as Lens formula.

Lens formula is applicable for convex as well as concave lenses.

Explanation:

$\frac{1}{v} -\frac{1}{u} =\frac{1}{f}$

Consider a convex lens with object AB kept on the principal axis. Two rays are considered such that one ray is parallel to the principal axis and after reflection, it passes through the focus. The second ray is towards the optical center such that it passes undeviated.

A’ is the point where the two rays intersect and also the image formed by point A. Point B image is obtained on the principal axis as the point B is on the principal axis.

As the object is perpendicular to the principal axis, even the object is perpendicular to the principal axis. To get the location of the image formed by point B, we need to draw a perpendicular from point A’ to the principal axis. Following are the things obtained after drawing the figure:

(CHECK THE IMAGE ATTACHED)

Therefore, this is known as Lens formula.

This was the derivation of Lens formula.