First slide

The lens

Question

The focal length of lens of refractive index 1.5 in air is 30 cm. When it is immersed in a liquid of refractive index $\frac{4}{3}$ , then its focal length in liquid will be

Moderate

A

30 cm
B

60 cm
C

120 cm
D

240 cm

Solution

$By using \frac{f_{l}}{f_{a}} = \frac{({aμ}_{g} - 1)}{(_{l} μ_{g} - 1)} \Rightarrow f_{w} = 4 f_{a} = 4 \times 30 = 120 cm .$

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