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Find the focal length and power of a con...

Find the focal length and power of a convex lens, which when placed in contact with a concave lens of focal length `25 cm` forms a real image `5` times the size of the object placed `20 cm` from the combination.

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The correct Answer is:
`-20 cm` ; concave
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PRADEEP-OPTICS-Exercise
  1. An object is placed at a distance of 1.5 m from a screen and a convex ...

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  2. Find the focal length and power of a convex lens, which when placed in...

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  3. Find the focal length and power of a convex lens, which when placed in...

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  4. Two lenses, one diverging of power 2 dioptre and the other converging ...

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  5. Two lenses of power + 10 D and - 5 D are placed in contact, (i) Calc...

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  6. A point object is placed 60 cm in front of a convex lens of focal leng...

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  7. A convex lens of focal length 15 cm, and a concave mirror of radius of...

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  8. Fig. shows a plane mirror M placed at a distance of 10 cm from a conca...

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  9. A monochromatic light is incident on the plane interface AB between tw...

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  10. The image of a needle placed 45 cm from a lens is formed on a screen p...

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  11. A biconvex thin lens is prepared from glass (mu=1.5), the two bounding...

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  12. A concave convex figure lens made of glas (mu=1.5) has surface of radi...

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  13. A converging beam of light forms a sharp image on a screen. A lens is ...

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  14. Rays of light are falling on a convex lens of focal length 40 cm. As s...

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  15. Which of the following colours has maximum wavelength

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  16. In vaccum, which colour travels fastest ?

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  17. In glass, the velocity of light is minimum for

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  18. The deviation delta of a ray on passing through a prism of small angle...

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  19. What is the relation between angle of prism A, angle of incidence i an...

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  20. When size of scatterer (x) is very much less than the wavelength (lamd...

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