Home
Class 11
PHYSICS
Two identical thin planoconvex glass len...

Two identical thin planoconvex glass lenses (refractive index `1.5)` each having radius of curvature of `20cm` are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index `1.7`. The focal length of the combination is

A

`-20` cm

B

`25` cm

C

`-50` cm

D

50 cm

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS

    TARGET PUBLICATION|Exercise EVALUATION TEST|16 Videos

  • RAY OPTICS

    TARGET PUBLICATION|Exercise CRITICALTHINKING|38 Videos

  • OPTICS

    TARGET PUBLICATION|Exercise EXERCISE|447 Videos

  • REFRACTION OF LIGHT

    TARGET PUBLICATION|Exercise EVALUATION TEST|15 Videos

Similar Questions

Explore conceptually related problems

Two plano-concave lenses (1 and 2) of glass of refractive index 1.5 have radii of curvature 20 cm and 10 cm. They are placed in contact with their curved surface towards each other and the space between them is filled with liquid of refractive index 4/3. Then the combination is

Two thin lenses of focal lengths f_(1) and f_(2) are in contact. The focal length of this combination is

Convex lens is made of glass of refractive index 1.5 If the radius of curvature of each of the two surfaces is 20 cm find the ratio of the powers of the lens, when placed in air to its power, when immersed in a liquid of refractive index 1.25 .

The focal length of a plano-convex lens is f and its refractive index is 1.5 it is kept over a plane galss plate with its curved surface touching the glass plate. The gap between the lens and the glass plate is filled by a liquid. As a result the effective focal length of the combination becomes 2f . Then the refractive index of the liquid is

A plano-convex lens is made of material having refractive index 1.5. The radius of curvature of curved surface is 60 cm. The focal length of the lens is ______ cm.

Two identical glass (mu_(g)=3//2) equiconvex lenses of focal length f are kept in contact. The space between the two lenses is filled with water (mu_(w)=4//3) . The focal length of the combination is

Two thin converging lenses of focal length 15 cm and 30 cm are held in contact with each other. The focal length of the combination is

The convex surface of a thin concavo-convex lens of glass of refractive index 1.5 has radius of curvature 10 cm. The concave surface has a radius of curvature 30 cm. The convex side is silvered and placed on a horizontal surface. Then where should a pin be placed on the optic axis such that its image is formed at the same place?

The radius of curvature of each surface of a biconcave lens made up of glass of refrative indx 1.5 is 30 cm. the focal length of the lens is

A double convex thin lens made of glass (refractive index mu = 1.5 ) has both radii of curvature of magnitude 20 cm . Incident light rays parallel to the axis of the lens will converge at a distance L such that

TARGET PUBLICATION-RAY OPTICS-COMPETITIVE THINKING
  1. In the figure an air less of raddi of curvature 10 cm (R1 = R2 = 10 cm...

    Text Solution

    |

  2. A plano-convex lens is made of material having refractive index 1.5. T...

    Text Solution

    |

  3. Two identical thin planoconvex glass lenses (refractive index 1.5) eac...

    Text Solution

    |

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

    Text Solution

    |

  5. In an optics experiment, with the position of the object fixed, a stud...

    Text Solution

    |

  6. The equiconvex lens has focal length f. If is cut perpendicular to the...

    Text Solution

    |

  7. An equiconvex lens is cut into two halves along (i) XOX' and (ii) YOY'...

    Text Solution

    |

  8. A converging beam of rays in incident on a diverging lens. Having pass...

    Text Solution

    |

  9. Graph of position of image vs position of point object from a convex l...

    Text Solution

    |

  10. Calculate the focal length of a reading glass of a person, if the dist...

    Text Solution

    |

  11. An object is located 4 m from the first of two thin converging lenses ...

    Text Solution

    |

  12. A beam of parallel rays is brought to focus by a planoconvex lens. A t...

    Text Solution

    |

  13. A plano-convex lens fits exactly into a plano-concave lens. Their plan...

    Text Solution

    |

  14. A plano-convex lens fits exactly into plano-concave lens as shown in t...

    Text Solution

    |

  15. Two lenses of power +12 and -2 dioptres are placed in contact. The com...

    Text Solution

    |

  16. A comvex lens and a concave lens are placed in contact. The ratio of m...

    Text Solution

    |

  17. Two identical glass (mu(g)=3//2) equiconvex lenses of focal length f a...

    Text Solution

    |

  18. Two identical equiconvex lenses, each of focal length 'f' are placed s...

    Text Solution

    |

  19. A bi-convex lens is formed with two thin plano convex lenses as shown ...

    Text Solution

    |

  20. Two convex lenses of focal length f1 and f2 are mounted coaxially sepa...

    Text Solution

    |