Question

the radii of curvature of the faces of a double convex lens are 10 cm and 15 cm. if focal length of the lens is 12 cm, find the refractive index of the material of the lens.

Answer 1

The refractive index of the material of the lens is 3.5.

Step-by-step explanation:

To find the refractive index of the material of the lens, we can use the lens maker's formula:

1/f = (n - 1) * ((1/R₁) - (1/R₂))

Where f is the focal length of the lens, n is the refractive index of the lens material, R₁ is the radius of curvature of one side of the lens, and R₂ is the radius of curvature of the other side of the lens.

Plugging in the given values:
f = 12 cm, R₁ = 10 cm, R₂ = 15 cm

1/12 = (n - 1) * ((1/10) - (1/15))

Simplifying the equation and solving for n:

n = 1 + (15/6)

n = 1 + 2.5 = 3.5

Therefore, the refractive index of the material of the lens is 3.5.