View Answer. 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. The lens should be thin so that the separation between the two refracting surface should be small. EASY. It … The pointer is arranged horizontally on the clamp of the retort stand, … The magnification of an object placed in front of a convex lens of focal length 2 0 c m is + 2. Let O be a point object lying in the rarer medium on the principal axis of the refracting surface X 1 P 1 Y 1. For water, Learn more about: It is useful to design lenses of desired focal length using surfaces of suitable radii of curvature. Let a concave lens have two spherical surfaces X 1 P 1 Y 1 and X 2 P 2 Y 2 having radius of curvature as R 1 and R 2 respectively. Write the formula for refraction of light on spherical (concave or convex) surface. What is … In that case R 1 is negative, R 2 positive and therefore, f is negative. Power of Lens $\displaystyle P = \frac{1}{f}$ where f should be in meters with proper sign … The lens maker’s equation for thin lenses is as given below as: where, f =focal length = refractive index of the material used = radius of curvature of sphere 1 =radius of curvature of sphere 2. STEP I. Refraction at X 1 P 1 Y 1. The incident ray OA after refraction at A bends towards the normal NC 1 and travel along AB. Here, n 1 < n 2. The lens maker’s formula relates the refractive index, focal length, and radii of curvature of the two spheres. The medium on either side of the lens should be same. Using the positive optical sign convention, the lens maker's formula states {1\over f} = (n-1)\left({{1\over R_1} - {1\over R_2}}\right) where f is the focal length, n is the index of refraction, and R_1 and R_2 are the radii of curvature of the two sides of the lens. Starting with an expression for refraction at a single spherical surface, obtain Lens Maker's Formula. View Answer. 2. Therefore from equation 3 and 4 we get, (n 1 /OB) + (n 1 /DI) =(n 1 /f) In the thin lens approximation, we can take B and D so close to the optical centre of … View Answer. The given convex lens is placed over the plane mirror. To obtain a magnification of − 2, the object has to be moved a distance equal to: MEDIUM. Derivation of Lens Maker Formula for a Concave Lens. Limitations of the lens maker’s formula: 1. View Answer. Establish lens formula f 1 = (n − 1) [R 1 1 − R 2 1 ] with its help. A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in … Note that the formula is true for a concave lens also. Hence obtain the expression for lens-maker's formula in the case of thin convex lens. 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. MEDIUM. Symbols used have their usual meaning. See also: Lens, Thin Lens Formula . MEDIUM. MEDIUM. The focal length of a glass slab of refractive index 1. View Answer. If any of the limitation is violated then we have to use the refraction at the curved surface formula for both the surfaces. Optics: Optical Components: Lenses: Lens Maker's Formula Using the positive optical sign convention, the lens … The given convex lens; The given liquid- water; Plane mirror; Retort stand; Pointer; Mercury; Meter scale; China dish; Real Lab Procedure: To find the focal length of the convex lens: The plane mirror is placed horizontally on the base of the retort stand with its reflecting surface upwards. 5 is. Equation (5) is known as Lens Maker’s Formula.