Search results
Learn how to derive the lens maker formula using refraction at two spherical surfaces and the thin lens approximation. Find the assumptions, limitations and applications of the formula for optical instruments.
- Lens Makers Formula - Definition, Formula And Solved Examples
The lens maker formula is utilized to create a lens with a...
- Lens Makers Formula - Definition, Formula And Solved Examples
Learn how to calculate the focal length of a thin lens using the lens makers formula, which relates the refractive index and the radii of curvature of its two surfaces. See solved examples and understand the types and properties of lenses.
- Focal Length and Radius of Curvature Definition
- Lens Maker Equation
- General Equation of A Convex Lens
- Lens Maker Formula For Concave Lens and Convex Lens
- Limitations of Lens Maker’s Formula
- Solved Examples
- Did You Know?
- GeneratedCaptionsTabForHeroSec
When parallel light rays are incident on a lens, the refracted rays converge to a point (for a converging lens) or appear to diverge from a point (for a diverging lens). This point is known as the focus of the lens. The distance between the optical centre and the focus is known as the focal length. The curved surfaces of a lens belong to two sphere...
The lens maker formula for a lens of thickness d and refractive index μ is given by, 1f=(μ−1)[1R1−1R2+(1−1μ)dR1R2]1f=(μ−1)[1R1−1R2+(1−1μ)dR1R2] Here, R1 and R2 are the radii of curvature of the two surfaces. For a thin lens, the thickness d is taken to be zero. The lens maker equation for a thin lens is given by, 1f=(μ−1)(1R1−1R2)1f=(μ−1)(1R1−1R2)
(image will be uploaded soon) A convex lens of negligible thickness is considered in the above figure. The refractive index of the lens is mu2, and it is kept in a medium of refractive index mu1. A point object O is kept in front of the lens. An image I' is formed due to refraction at the first surface with a radius of curvature R1. This intermedia...
For a concave lens, R1 is negative and R2 is positive. The lens maker formula for the concave lens is given by, 1f=−(μ1μ2−1)(1R1+1R2)1f=−(μ1μ2−1)(1R1+1R2) For a convex lens, R1 is positive and R2 is negative. The lens maker formula takes the following form, 1f=−(μ1μ2−1)(1R1+1R2)1f=−(μ1μ2−1)(1R1+1R2)
The limitations of the lens maker’s formula are as follows: 1. The lens needs to be thin. This is because the distance between the two refractive surfaces is also very small. 2. The medium on both sides of the lens needs to be the same. If the limitation is violated, refraction at the surface formula is used for both surfaces.
1.The focal length of a lens, made up of glass, is 5 cm in air. What would be the focal length of the same lens in water? The refractive indices of glass and water are 1.51 and 1.33 respectively. Solution:The radii of curvature of the lens are R1 and R2. The focal length of the lens in the air is fa= 5 cm. The refractive index of glass is μg = 1.51...
If a convex lens, having focal length f, is cut along the principal axis, both the resulting pieces will have the same focal length f.Water droplets can be considered as convex lenses and the lens maker formula is applicable.The reciprocal of the focal length is called the refractive power that has units dioptre (inverse meter).Learn how to calculate the focal length of a lens using the lens maker's formula, which relates the refractive index, radii of curvature and thickness of the lens. Find out the sign convention, general equation and limitations of the formula for convex and concave lenses.
Learn how to use the lensmaker's equation to calculate the focal length and radius of curvature of a thin lens. The web page also explains the concepts of refraction, thin lens, and optical power with examples and diagrams.
The lens maker formula is utilized to create a lens with a defined focal length. Learn more about lens markers formula and solved example.
- 10 min
Learn how to derive the lens makers formula for thin lenses using refraction at curved surfaces. See how to apply the formula to find the focal length and image distance of a lens with different refractive indices and radii of curvature.
- 14 min
- Mahesh Shenoy
Learn how to calculate the power and focal length of a thin lens using the Lens-Maker's Formula. Find out how the index of refraction and the radii of curvature affect the lens strength and the human eye.
