Question

A convex lens of focal length 12 cm is made of glass

Answer 1

Answer:

then its power will

1/0.12 Diopter

because focal length always taken in m

Answer 2

The focal length of lens when its immersed in liquid is 30 cm.

Explanation:

Given that,

Focal length = 12 cm

Suppose refractive index of glass of $\mu=\dfrac{3}{2}$

Determine the focal length of lens when its immersed in liquid of $\mu=\dfrac{5}{4}$

We need to calculate the focal length of lens its immersed in liquid

Using formula of lens

$\dfrac{f'}{f}=\dfrac{\mu_{g}-1}{\dfrac{\mu_{g}}{\mu_{l}}-1}$

Put the value into the formula

$\dfrac{f'}{12}=\dfrac{\dfrac{3}{2}-1}{\dfrac{\dfrac{3}{2}}{\dfrac{5}{4}}-1}$

$f'=12\times\dfrac{\dfrac{3}{2}-1}{\dfrac{\dfrac{3}{2}}{\dfrac{5}{4}}-1}$

$f'=30\ cm$

Hence, The focal length of lens when its immersed in liquid is 30 cm.

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Topic :

https://brainly.in/question/8515893