Home
Class 12
PHYSICS
A thin convex lens of focal length 'f' i...

A thin convex lens of focal length 'f' is put on a plane mirror as shown in the figure . When an object is kept at a distance 'a' from the lens - mirror combination , its image is formed at a distance `(a)/(3)` in front of the combination . The value of 'a' is :-

Text Solution

Verified by Experts

The correct Answer is:
D
`(1)/(f_("eq")) = (1)/(f_(m)) - (2)/(
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

An object is placed at a distance of 30 cm from a concave mirror and its real image is formed at a distance of 30 cm from the mirror. The focal length of the mirror is

A biconvex lens of focal length 15cm is in front of a plane mirror. The distance between the lens and the mirror is 10cm. A small object is kept at distance of 30cm from the lens. The final image is

A convex lens of focal length f forms an image which is 1/3 times the size of the object. Then, the distance of object from the lens is

A convex lens of focal length f produces an image 1/n times than that of the size of the object. The distance of the object from the lens is:

An object, a convex lens of focal length 20 cm and a plane mirror are arranged as shown in the figure. How far behind the mirror is the second image formed?

A convex lens of focal length 15 cm is placed on a plane mirror. An object is placed at 30 cm from the lens. The image is

A convex lens of focal length 30 cm , a concave lens of focal length 120 cm , and a plane mirror are arranged as shown . For an object kept at a distance of 60 cm from the convex lens, the final image, formed by the combination , is a real image , at a distance of : |"Focal length" | = |"Focal length"| = 30 cm " " =120 cm

A thin convex lens of focal length 30 cm is placed in front of a plane mirror. An object is placed at a distance x from the lens (not in between lens and mirror ) so that its final image coincides with itself. Then, the value of x is

A convex mirror has a focal length f. A real object is placed at a distance f in front of it from the pole produces an image at

An object is placed at a distance of f/2 from a convex lens of focal length f. The image will be

ALLEN-GEOMETRICAL OPTICS-EXERCISE-05 (A)
  1. The XY plane is the boundary between two tranparednt media. Medium 1 w...

    Text Solution

    |

  2. A car is fitted with a convex side-view mirror of focal length 20 cm A...

    Text Solution

    |

  3. When monochromatic red light is used instead of blue light in a convex...

    Text Solution

    |

  4. A beaker contains water up to a height h1 and K oil above water up to...

    Text Solution

    |

  5. An object 2.4 m in front of a lens forms a sharp image on a film 12cm ...

    Text Solution

    |

  6. The graph between angle of deviation (delta) and angle of incidence (i...

    Text Solution

    |

  7. Diameter of plano-convex lens is 6 cm and thickness at the centre is 3...

    Text Solution

    |

  8. A thin convex lens made from crown glass (mu = 3/2), has focal length...

    Text Solution

    |

  9. A green light is incident from the water to the air – water interface ...

    Text Solution

    |

  10. You are asked to design a shaving mirror assuming that a person keeps ...

    Text Solution

    |

  11. A thin convex lens of focal length 'f' is put on a plane mirror as sho...

    Text Solution

    |

  12. Assuming human pupil to have a radius of 0.25 cm and a comfortable vie...

    Text Solution

    |

  13. Monochromatic light is incident on a glass prism of angle A. If the re...

    Text Solution

    |

  14. An observer looks at a distant tree of height 10 m with a telescope of...

    Text Solution

    |

  15. In an experiment for determination of refractive index of glass of a p...

    Text Solution

    |

  16. To find the focal length of a convex mirror , a student records the fo...

    Text Solution

    |

  17. A convex lens of focal length 30 cm , a concave lens of focal length 1...

    Text Solution

    |

  18. Two stars are 10 light years away from the earth. They are seen throug...

    Text Solution

    |

  19. To determine refractive index of glass slab using a travelling microsc...

    Text Solution

    |

  20. A hemispherical glass body of radius 10 cm and refractive index 1.5 is...

    Text Solution

    |