To obtain this type of numerical information, it is necessary to use the Lens Equation and the Magnification Equation. Thus, 1 f = (n −1) 1 R1 + 1 R2 , (9) which is the lensmaker’s formula. class-12 Physics Optics Ray diagrams of Optics dispersion through a Prism lens maker formulas Kanwaljit Singh Mand h Figure 2: Ray Diagram for Lens Analysis of air as 1, Snell’s law holds that n sinθ1= sinθ2. Lens Maker's Equation. CO = P 1 O = u. Ray Optics applets I have made. Important relationships, including the lens makers' equation (see below) and the lateral magnification are calculated and displayed in the tutorial window as control parameters are adjusted. Concave and Convex Mirror Ray Diagram. Explain why both the objective and eye pieces of a compound microscope must have short focal lens . The following assumptions are taken for the derivation of lens maker formula. Reflection and Refraction. Prism Dispersion. It follows from the refraction due to convex spherical surface XP 1 Y. Or Draw the labelled ray diagram for the formation of image by a compound microscope . The Lens Maker’s Equation for Thin Lenses: \frac 1f ~= ~ (n-1) \left (\frac {1} {R_1}~-~ \frac {1} {R_2} \right) SF017 SF027 51 1.5 Thin Lenses Formula and Lens maker’s Equation {Considering the ray diagram of refraction for 2 spherical surfaces as shown in figure below. V W F To obtain this type of numerical information, it is necessary to use the Lens Equation and the Magnification Equation. Derive the expression for the total magnification of a compound microscope . The refracted ray from A suffers a second refraction on the surface XP 2 Y and emerges along BI. CI 1 = P 1 I 1 = V 1 (as the lens is thin) CC 1 = P 1 C 1 = R 1. If first medium is air and refractive index of material of lens be n , then 1 n 2 = n, therefore equation (v) may be written as (b) Power of a Lens: The power of a lens is its ability to deviate the rays towards its principal axis. Lens Pair. (CBSE 2009) Substituting this in the angle between the … Here the object distance is. Plane Mirror in 3D. Lens maker’s formula: (a) Lens maker’s formula : Consider a thin double convex lens of refractive index n 2 placed in a medium of refractive index n 1. While a ray diagram may help one determine the approximate location and size of the image, it will not provide numerical information about image distance and image size. Lenses. While a ray diagram may help one determine the approximate location and size of the image, it will not provide numerical information about image distance and image size. Simple thin lenses are designed by using the so-called lens-maker’s formula: 1 f = n 2 n 1! The derivation of lens maker formula is provided here so that aspirants can understand the concept more effectively. Hence , derive the expression of lens maker's formula . Let B and D be the poles, C 1 and C 2 be the centres of curvature and R 1 and R 2 be the radii of curvature of the two lens surfaces ABC and ADC, respectively. If first medium is air and refractive index of material of lens be n, then 1 n 2 = n, therefore equation (v) may be written as (b) Ray Diagram: The ray diagram of image formation for an object between focus (F) and pole (P) of … This formula is called Lens-Maker’s formula. O C 1 II C 2 1 P 1 P 2 I2 B E A D u1 v1 v2 r1 r2 t n1 t −v1 n2 n1 SF027 52 {By using the equation of spherical refracting surface, the refraction by first surface AB and second surface DE are given by Ray Optics ... Two People Looking in a Plane Mirror. Assumptions. Snell's Law for Spherical and Parabolic Lenses. If first medium is air and refractive index of material of lens be n, then 1 n 2 = n, therefore equation (v) may be written as (b) Ray Diagram: The ray diagram of image formation for an object between focus (F) and pole (P) of a concave mirror is shown in fig. Ray diagrams for such lenses are drawn using: a ray from the top of the object through the middle of the lens; a ray from the top of the object parallel to the principal axis which the lens refracts so it seems to come from the focal point. 1" # $ % & ' 1 r 1 + 1 r 2" # $ % & ' Where f is the focal length, n 2 is the index of refraction of the lens material, n 1 is the index of the surrounding material, and r 1 and r 2 are the radii of … Spherical Mirror Multiray. Here, n 1 < n 2. This formula is called Lens-Maker’s formula. Therefore I is the final real image of O. This formula is called Lens-Maker’s formula. Writing the lens equation in terms of the object and image distances, 1 o + 1 i = 1 f. (8) But o1 and i2 are the object and image distances of the whole lens, so o1 = o and i2 = i. Spherical vs. Parabolic Mirrors. Assuming small angles (paraxial rays), we now approximate the sines of the angles with the angles themselves so that nθ1≈ θ2. The lens maker’s equation is another formula used for lenses that give us a relationship between the focal length, refractive index, and radii of curvature of the two spheres used in lenses. Lens manufacturers commonly use the lens maker formula for manufacturing lenses of the desired focal length. Lens Maker Formula Derivation. lens, the lens equation is the same but the value of fis nownegative.