First slide

The lens

Question

Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal length of lens when immersed in a liquid of refractive index of 1.25 will be

Moderate

A

10 cm
B

2.5 cm
C

5 cm
D

7.5 cm

Solution

$\frac{f_{l}}{f_{a}} = \frac{{aμ}_{g} - 1}{_{l} μ_{g} - 1} = \frac{{aμ}_{g} - 1}{\frac{_{a} μ_{g}}{_{a} μ_{l}} - 1} \Rightarrow \frac{f_{l}}{2} = \frac{1 .5 - 1}{\frac{1 .5}{1 .25} - 1} \Rightarrow f_{l} = 5 cm$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App