Home
Class 11
PHYSICS
When two thin lenses are kept in contanc...

When two thin lenses are kept in contanct, the focal length of the combination is

A

the geometrical mean of the two focal lengths.

B

the same as the larger focal length.

C

greater than either focal length.

D

smaller than either focal length.

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • Motion in a plane

    TARGET PUBLICATION|Exercise Exercise|340 Videos

  • RAY OPTICS

    TARGET PUBLICATION|Exercise EVALUATION TEST|16 Videos

Similar Questions

Explore conceptually related problems

Two lenses of power +12 and -2 dioptres are placed in contact. The combined focal length of the combination will be

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

When two lenses are kept touching each other, the power of the combined lens is equal to the sum of their individual powers.

A comvex lens and a concave lens are placed in contact. The ratio of magnitude of the power of the convex lens to that of the concave lens is 4:3. If the focal length of the convex lens is 12 cm, then the focal length of the combination will be

A plano-convex lens fits exactly into a plano-concave lens. Their plane surfaces are parallel to each other. If the lenses are made of different material of refractive indices mu_(1) and mu_(2) and R is the radius of curvature of the curved surface of the lenses, then focal length of the combination is

Two similar thin equiconvex lenses, of focal length f each, are kept coaxially in contact with each other such that the focal length of the combination is F_1 . When the space between the two lenses is filled with glycerin (which has the same refractive index (mu = 1.5) as that of glass) then the equivalent focal length is f_2 . The ratio F_1 : F_2 will be:

Fill in the blanks : If two lenses with focal lengths 10cm and 20 cm respectively are kept in contact with each other , the effective power of the combination is ………….

Two thin lenses may be combined so as to

TARGET PUBLICATION-OPTICS-EXERCISE
  1. The power of a thin convex lens (""(a) mu(g)=1.5) is +5.0 D. When it i...

    Text Solution

    |

  2. Figure given below shows a beam of light converging at point P. When a...

    Text Solution

    |

  3. When two thin lenses are kept in contanct, the focal length of the com...

    Text Solution

    |

  4. In the figure an air less of raddi of curvature 10 cm (R1 = R2 = 10 cm...

    Text Solution

    |

  5. The ray diagram could be correct.

    Text Solution

    |

  6. How does the magnification (m) of the real image formed by a lens vary...

    Text Solution

    |

  7. As shown in the figure, the liquids L1, L2 and L3 have refractive indi...

    Text Solution

    |

  8. Twon similar plano-covexlenses are combined together in three differen...

    Text Solution

    |

  9. A beam of parallel rays is brought to a focus by a plano-convex lens. ...

    Text Solution

    |

  10. A concave and convex and have the same focal length of 20 cm and are p...

    Text Solution

    |

  11. The figure shows the view through the eye piece of a prism spectromete...

    Text Solution

    |

  12. During dispersion of white light by prism placed in air, for a particu...

    Text Solution

    |

  13. When a white light passes through a hollow prism, then there is

    Text Solution

    |

  14. A narrow beam of white light passes through glass slab having parallel...

    Text Solution

    |

  15. A beam of light composed of red and green rays is incident obliquely a...

    Text Solution

    |

  16. A given ray of light suffers minimum deviation in an equilateral prism...

    Text Solution

    |

  17. A prism is placed in water. The angle of minimum deviation.

    Text Solution

    |

  18. A ray of light is incident on an equilateral glass prism placed on a h...

    Text Solution

    |

  19. A ray of light is incident on a 60^(@) prism at the minimum of deviati...

    Text Solution

    |

  20. A prism having refractive index sqrt(2) and refracting angle 30^(@), h...

    Text Solution

    |