Home
Class 11
PHYSICS
Two thin converging lenses of focal leng...

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

A

45 cm

B

15 cm

C

10 cm

D

9 cm

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

If a concave lens of focal length 12 cm and a convex lens of focal length 20 cm are kept in contact with each other . (i) Find be the focal length of the combination ? (ii) What will be the behaviour of the combination ?

If a convex lens of focal length 20 cm and a concave lens of focal length 30 cm are kept in contact with each other . (i) What will be the focal length of the combination ? (ii) What will be the power of the combination ? (iii) What will be the behaviour of the combination ?

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:

If two convex lenses of focal lengths 10 cm and 5 cm are kept in contact with each other , What is their combined focal length ?

Answer the following questions : If two lenses of focal length f_1 and f_2 are kept in contact with each other , state the formula for the focal length of the combination . If p_1 and P_2 are the power of these lenses, state the formula for the power of the combination .

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 ………….

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

TARGET PUBLICATION-OPTICS-EXERCISE
  1. Two thin lenses may be combined so as to

    Text Solution

    |

  2. Two thin lenses with focal lenghts f(1) and f(2) make a lens of focal ...

    Text Solution

    |

  3. Two thin converging lenses of focal length 15 cm and 30 cm are held i...

    Text Solution

    |

  4. What is the focal of the combination of a convex lens of focal length...

    Text Solution

    |

  5. Two thin lenses, aone convex of focal length 10 cm and other concave l...

    Text Solution

    |

  6. Two lenses of power +12and-2 dioptres are placed in contact. What will...

    Text Solution

    |

  7. When two or more lnses of magnification m(1) ,m(2), m(3) are kept in c...

    Text Solution

    |

  8. The separation of whtie light into its constituent colours after passi...

    Text Solution

    |

  9. A shaped triangular transparent block havin three rectangular planes ...

    Text Solution

    |

  10. The angle between the two-plane rectangular refracing surface of a pri...

    Text Solution

    |

  11. The rectangular face opposite to the refracting edge is called .

    Text Solution

    |

  12. The refractivity of the material of the prism is given by

    Text Solution

    |

  13. A glass prism placed in a homogeneous transparent medium will deviate ...

    Text Solution

    |

  14. As the refractive index of the material of prism for different colours...

    Text Solution

    |

  15. When while light passes through prism then constituent colours are obt...

    Text Solution

    |

  16. A prism splits a beam of white light into its constituent colours. Thi...

    Text Solution

    |

  17. Dispersion of light is shown in the following diagram, select the CORR...

    Text Solution

    |

  18. The angle between incident ray and ray is called angle of deviation.

    Text Solution

    |

  19. When white light passes through prism, the angle of deviation is

    Text Solution

    |

  20. While deriving prism formula, angle of deviation is minimum if

    Text Solution

    |