Question

write a formula for refraction at curved surface object lies at rarer medium find equivalent focal length of a system of two thin lenses in contact having focal length +20cm and power -2.5D​

Answer 1

Explanation:

Here R

1

= 20 cm, R

2

= -40 cm, f = 20 cm

Using lens maker's formula we get,

20

1

=(μ−1)(

20

1

+

40

1

)

20

1

=(μ−1)

40

3

⇒μ=

3

5

Hope it helps :)