Question

Q.12. (a) Write the relation of Lens formula?

(b)Write the relation of Power with focal length?

(c) Write the relation of Magnification formula?

(d) Define principle focus of lens?

(e) Give the relation between focal length and radius of curvature?​

Answer 1

Answer:

(a) Calculating magnification with the help of lens formula:

Magnification of a lens is defined as the ratio of the height of an image to the height of an object. It is also given in terms of image distance and object distance. It is equal to the ratio of image distance to that of object distance.

(b) The power of a lens is defined as the reciprocal of its focal length in meters, or D = 1/f, where D is the power in diopters and f is the focal length in meters. Lens surface power can be found with the index of refraction and radius of curvature.

(c) Magnification (m) = h/h'

And h' is the image height and h is the object height.

(d) The principal focus of a convex lens is defined as the point on which the principal axis of the light is parallel to the principal axis that converges after the refraction from the lens. The principal focus of concave lens is when the light rays get diverged and appear to form a single point.

(e) The radius of curvature (r) is the radius of the lens that forms a complete sphere. ... Therefore, the radius of curvature is twice the focal length.

Hope it helps you...