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At what distance from a convex lens of f...

At what distance from a convex lens of focal length `30cm` an object should be placed so that the size of image be `(1)/(4) `that of object?

A

30 cm

B

60 cm

C

15 cm

D

150 cm

Text Solution

Verified by Experts

The correct Answer is:
D
(d) Image is real, because virtual imafe is enlarged.
`therefore 1/v-1/u=1/for 1/(x//4)+1/x=1/30(thereforeu=-x)`
`5/x=1/30`
`therefore` x=150 cm
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DC PANDEY-RAY OPTICS-Checkpoint 9.4
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  5. At what distance from a convex lens of focal length 30cm an object sh...

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  6. A plano - convex lens is made of flint glass. Its focal length is

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  9. An object is placed at 10 cm from a lens and real image is formed with...

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  10. The real image which is exactly equal to the size of an object is to b...

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  11. A plano-convex lens of curvature of 30 cm and refractive index 1.5 pro...

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  12. The minimum distance between an object and its real image formed by a ...

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  13. A convex lens of refractive index 3/2 has a power of 2.5^(@). If it is...

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  14. Two thin lenses of focal length f(1) and f(2) are in contact and coaxi...

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  15. Two thin lenses, one of focal length + 60 cm and the other of focal le...

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  16. A convex lens of focal length 40 cm is in contact with a concave lens ...

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  18. A convex lens has a focal length f. It is cut into two parts along the...

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