A biconvex lens has radii of curvature, 20 cm each. If the refractive index of the material of the lens is 1.5, the power of the lens is [NEET 2022]

Question

Accepted Answer

Correct answer: B. (b) For a biconvex lens, R_1=+20 cm R_2=-20 cmand =1.5 By using lens Maker's formula, we have, 1f= ( -1 )( 1R_1- 1R_2) = (1.5-1 )( 120- 1-20) =0.5 ( 220 ) 1f=0.5 110 ⇒f= 100.5 ⇒f=20 cm=0.2 m ∴ Power of the lens, P= 1f (in metre) = 10.2=+5D

$A biconvex lens has radii of curvature, 20 cm each. If the refractive index of the material of the lens is 1.5, the power of the lens is [NEET 2022]$

Solution

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