View Answer. 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. The lens maker’s formula relates the refractive index, focal length, and radii of curvature of the two spheres. STEP I. Refraction at X 1 P 1 Y 1. 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. View Answer. 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 … For water, Learn more about: View Answer. 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. The magnification of an object placed in front of a convex lens of focal length 2 0 c m is + 2. Symbols used have their usual meaning. Starting with an expression for refraction at a single spherical surface, obtain Lens Maker's Formula. Write the formula for refraction of light on spherical (concave or convex) surface. It … The incident ray OA after refraction at A bends towards the normal NC 1 and travel along AB. The lens should be thin so that the separation between the two refracting surface should be small. Here, n 1 < n 2. In that case R 1 is negative, R 2 positive and therefore, f is negative. A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in … What is … The pointer is arranged horizontally on the clamp of the retort stand, … 2. MEDIUM. Optics: Optical Components: Lenses: Lens Maker's Formula Using the positive optical sign convention, the lens … Hence obtain the expression for lens-maker's formula in the case of thin convex lens. The focal length of a glass slab of refractive index 1. Limitations of the lens maker’s formula: 1. 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. Power of Lens $\displaystyle P = \frac{1}{f}$ where f should be in meters with proper sign … MEDIUM. Note that the formula is true for a concave lens also. See also: Lens, Thin Lens Formula . Equation (5) is known as Lens Maker’s Formula. View Answer. Derivation of Lens Maker Formula for a Concave Lens. MEDIUM. The given convex lens is placed over the plane mirror. The medium on either side of the lens should be same. It is useful to design lenses of desired focal length using surfaces of suitable radii of curvature. 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. If any of the limitation is violated then we have to use the refraction at the curved surface formula for both the surfaces. To obtain a magnification of − 2, the object has to be moved a distance equal to: MEDIUM. Establish lens formula f 1 = (n − 1) [R 1 1 − R 2 1 ] with its help. 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. 5 is. EASY. 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. View Answer.