Lens Formula and Magnification
If the thickness of a lens is negligible in comparison to the radius of curvature, it is a thin lens. Thin lens formula is used to determine a relation between the focal length of the lens, the distance of the object, and the distance of the image. The lens formula is given as:
(1/f) = (1/v) – (1/u)
- f = focal length of the lens
- v = distance of the image from the optical centre
- u = distance of the object from the optical centre
The parameters in above formula assume signs according to sign convention of lens.
Magnification of Lens
Magnification of lens is the ratio of the height of the image produced and the height of the object. The magnification formula is given as
m = hi/ho = height of image/height of object
The another formula for magnification in terms of image and object distance is given as follows:
m = v/u = image distance/object distance
- If m > 1 then image is larger than object
- If m < 1 then image is smaller than object
- If m = 1 then image size is equal to object
Ray Optics – Definition, Formula, Applications
Ray Optics is the study of properties of light and optical instruments by assuming that light travels in a straight line. It is also known as geometrical optics, which deals with the geometry of light. Light always travels in a straight line, and the direction in which the light rays propagate is called the ray of light. It studies the principles and laws governing the propagation of light, particularly in the absence of wave effects such as interference and diffraction.
In this article, we will learn about ray optics, reflection, refraction, concave and convex mirrors, lenses, and formulas related to them.