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The distance between an object and the s...

The distance between an object and the screen is 100cm. A lens produces an image on the screen when the lens is placed at either of the positions 40cm apart. The power of the lens is nearly

A

`~~3D`

B

`~~5D`

C

`~~7D`

D

`~~9D`

Text Solution

Verified by Experts

The correct Answer is:
B
`f=(D^(2)-x^(2))/4`
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NARAYNA-RAY OPTICS AND OPTICAL INSTRAUMENTS -EXERCISE-2 (C.W)(REFRACTION THROUGH SPHERICAL SURFACES )
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  2. A convex lens of focal length f is placed somewhere in between an obje...

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  3. The distance between an object and the screen is 100cm. A lens produce...

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  4. Three lenses in contact have a combined focal length of 12 cm. When th...

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  5. Arrange the following combinations in the increasing order of focal le...

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  6. A thin converging lens forms the real image of certain real object mag...

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  7. When an object is at distances x and y from a lens, a real image and a...

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  8. Two thin convex lenses of focal lengths f(1) and f(2) are arranged coa...

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  9. A plano-convex lens, when silvered at its plane surface is equivalent ...

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  10. A thin equiconvex lens has focal length 10 cm and refractive index 1.5...

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  11. Four lenses are made from the same type of glass, the radius of curvat...

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  12. 4 A thin liquid convex lens is formed in glass. Refractive index of li...

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  13. A thin converging lens of refractive index 1.5 has a focal power of 5 ...

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  14. The focal lengths of a lens are in the ratio 8:3 when it is immersed i...

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  15. v22

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  16. A plano convex lens has a thickness of 6cm. Its radius of curvature is...

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  17. Two plano-concave lenses of glass of refractive index 1.5 have radii ...

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  18. The power of a double convex lens of radius of curvature R each is Y. ...

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  19. A thin glass (refractive index 1.5) lens has optical power of -8D in a...

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  20. v34

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