Question

A double concave lens has two radii of curvature -10cm and -20cm. Calculate the focal length of this lens if the refractive index of glass is 1.5

Answer 1

Answer:

Explanation:

We know the Lens maker formula:

1/f=(u-1)((1/R1)-(1/R2)), where f is focal length,u is refractive index and R is radius of curvature.

So,1/f= -1/40So, focal length=-40cm.

Hope you understood

Answer 2

Answer:

hey watch the above pic for ur answer of the question