A lens of power 5 Diopter in air is immersed in water of refractive index 4-3- If refractive index of glass of lens is 3-2- Power of lens in water in Diopter is Write upto two digits after the decimal point-

By 1/f=(μ 1)2/R⇒ S=1/2×2/R R = 20 cm ........ (1) Using lens makers formula, 1/f = (μ_2/μ_1 1) (1/R_1 1/R_2) nbsp;= (9/8 1)(2/20) = 1/80 cm = 1.25 D ...

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Standard XII

Physics

Dimensional Analysis

A lens of pow...

Question

A lens of power 5 Diopter in air is immersed in water of refractive index $\frac{4}{3}$ . If refractive index of glass of lens is $\frac{3}{2}$ . Power of lens in water in Diopter is (Write upto two digits after the decimal point.)

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Solution

By $\frac{1}{f} = (μ - 1) \frac{2}{R} \Rightarrow S = \frac{1}{2} \times \frac{2}{R}$

R = 20 cm ........ (1)

Using lens makers formula,
$\frac{1}{f} = (\frac{μ_{2}}{μ_{1}} - 1) (\frac{1}{R_{1}} - \frac{1}{R_{2}}) = (\frac{9}{8} - 1) (\frac{2}{20}) = \frac{1}{80 c m} = 1.25 D$

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A lens of power 5 Diopter in air is immersed in water of refractive index 43. If refractive index of glass of lens is 32. Power of lens in water in Diopter is (Write upto two digits after the decimal point.)

By 1f=(μ−1)2R⇒S=12×2R R = 20 cm ........ (1) Using lens makers formula, 1f=(μ2μ1−1)(1R1−1R2)=(98−1)(220)=180cm=1.25D

A lens of power 5 Diopter in air is immersed in water of refractive index $\frac{4}{3}$ . If refractive index of glass of lens is $\frac{3}{2}$ . Power of lens in water in Diopter is (Write upto two digits after the decimal point.)

By $\frac{1}{f} = (μ - 1) \frac{2}{R} \Rightarrow S = \frac{1}{2} \times \frac{2}{R}$

R = 20 cm ........ (1)

Using lens makers formula,
$\frac{1}{f} = (\frac{μ_{2}}{μ_{1}} - 1) (\frac{1}{R_{1}} - \frac{1}{R_{2}}) = (\frac{9}{8} - 1) (\frac{2}{20}) = \frac{1}{80 c m} = 1.25 D$