Request a call back

A converging lens of refractive index 1.5 and of focal length 15 cm in air, has the same radii of curvature for both sides. if it is immersed in a liquid of refractive index 1.7, Calculate the focal length of the lens in the liquid?
Asked by satya785583 | 24 Mar, 2019, 10:58: AM

Refractive index of the lens material, aμg =1.5

Focal length of the lens in air, fair = 15 cm

Using lens makers formula-

1/fair = (aμg-1) [1/R1 -1/R2]

1/15 = (1.5-1)[1/R1 -1/R2]

[1/R1 -1/R2] = 1/7.5

Refractive index of liquid, aμL =1.7

Refractive index of lens glass with respect to liquid, Lμg=aμg /aμL

Lμg= 1.5/1.7 = 0.88

Let the focal length of the lens in liquid is-

1/fliquid = (Lμg-1)[1/R1 -1/R2]

1/fliquid = (0.88-1)[1/7.5]

= -0.015

So,fliquid = -66.67 cm.

Answered by Ankit K | 24 Mar, 2019, 10:18: PM

## Concept Videos

CBSE 12-science - Physics
Asked by r01raunak | 23 May, 2023, 10:24: AM
CBSE 12-science - Physics
Asked by komalbrar0987 | 17 May, 2023, 06:15: PM
CBSE 12-science - Physics
Asked by marvellouskyndiah | 17 May, 2023, 08:07: AM
CBSE 12-science - Physics
Asked by Abhishek | 23 Mar, 2023, 08:37: PM