Home
Class 12
PHYSICS
Where should an object be placed from a ...

Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?

A

50 cm

B

60 cm

C

`-50 cm`

D

`-30 cm`

Text Solution

Verified by Experts

The correct Answer is:
D
(d) For real image from converging lens,
m=-2
`therefore` Magnification ,m`=f/(f+u)rArr-2=f/(u+f)=20/(u+20)`
`rArr` u=-30 cm
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS

    DC PANDEY|Exercise Checkpoint 9.5|10 Videos

  • RAY OPTICS

    DC PANDEY|Exercise Checkpoint 9.6|20 Videos

  • RAY OPTICS

    DC PANDEY|Exercise Checkpoint 9.3|20 Videos

  • NUCLEI

    DC PANDEY|Exercise C MADICAL ENTRANCES GALLERY|46 Videos

  • REFLECTION OF LIGHT

    DC PANDEY|Exercise Subjective|9 Videos

Similar Questions

Explore conceptually related problems

Where should an object be placed from a converging lens of focal length 10 c, so as to obtain a virtual image of magnification 2 ?

Calculate the distance of an object of height h from a concave mirror of focal length 10 cm so as to obtain a real image of magnification 2 .

An object is placed 80 cm from converging lens of focal length 25 cm. What is the nature of image?

At what distance an object must be placed from a lens of focal length 15 cm to get an inverted image of unit magnification ?

At what distance should an object be placed from a convex lens of focal length 18 cm to obtain an image at 36 cm from it ? What will be the magnification produced in this case?

At what distance from a converging lens of focal length 12 cm must an object be placed in order than an image of magnification 1 will be produced?

The magnification of an object plac ed in front of a convex lens of focal length 20 cm is +2. to obtain a magnification of -2. the object will have to be moved a distance equal to

DC PANDEY-RAY OPTICS-Checkpoint 9.4
  1. An air bubble contained inside water. It behaves as

    Text Solution

    |

  2. A convex lens has a focal length of 20 cm. It is used to form an image...

    Text Solution

    |

  3. In the figure, an air lens of radii of curvature 10 cm (R(1)=R(2)=10 c...

    Text Solution

    |

  4. A plano convex lens is made of glass of refractive index 1.5. The radi...

    Text Solution

    |

  5. At what distance from a convex lens of focal length 30cm an object sh...

    Text Solution

    |

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

    Text Solution

    |

  7. Distance of an object from a concave lens of focal length 20 cm is 40 ...

    Text Solution

    |

  8. Where should an object be placed from a converging lens of focal lengt...

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

  17. Two similar plano-convex lenses are combined together in three differe...

    Text Solution

    |

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

    Text Solution

    |

  19. A converging lens is used to form an image on a screen. When the upper...

    Text Solution

    |

  20. If in a plano-convex lens, the radius of curvature of the convex surfa...

    Text Solution

    |