The radius of curvature of the convex face of a plano convex lens is 12cm and the refractive index of the material of the lends 1.5. Then, the focal length of the lens isA. 6cmB. 12cmC. 18cmD. 24cm

The radius of curvature of the convex face of a plano convex lens is 1

1.	The radius of curvature of the convex face of a plano convex lens is 12cm and the refractive index of the material of the lends 1.5. Then, the focal length of the lens isA. 6cmB. 12cmC. 18cmD. 24cm
Answer» Correct Answer - D We know that, `(1)/(f)=(n-1)(1)/(R )` Given, R=12cm and r=1.5 Here, `f=(R)/(n-1)=(12)/(1.5-1)=(12)/(0.5)=24cm`

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The radius of curvature of the convex face of a plano convex lens is 12cm and the refractive index of the material of the lends 1.5. Then, the focal length of the lens isA. 6cmB. 12cmC. 18cmD. 24cm

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