Question

Find the focal length of a equi convex lens of radius of curvature 10 cm and refractive index of 1.5

Answer 1

According to lens makers formula,

1/f=(u-1)(1/R1-1/R2)

Where,

u is refractive index of lens given

R1,R2 are radii of curvature of given lens

I am assuming that radii of curvature are equal

R1=R and R2=-R

1/f=0.5×2/10

Therefore,f=10cm