Home
Class 10
PHYSICS
Find the power of a concave lens of foca...

Find the power of a concave lens of focal length `2 m`.

Text Solution

Verified by Experts

Focal length of concave lens, f = 2 m Power of lens, P=1/f = 1/(-2) = -0.5D
Promotional Banner

Topper's Solved these Questions

  • LIGHT - REFLECTION AND REFRACTION

    NCERT ENGLISH|Exercise Exercise|28 Videos

  • ELECTRICITY

    NCERT ENGLISH|Exercise Exercise|41 Videos

  • MAGNETIC EFFECTS OF ELECTRIC CURRENT SCIENCE

    NCERT ENGLISH|Exercise Solved Examples|2 Videos

Similar Questions

Explore conceptually related problems

A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. The power of the combination is

A convex lens of power +2.5 D is in contact with a concave lens of focal length 25 cm. The power of combination is

What is the optical power in dioptre of a concave lens of focal length 50 cm?

A convex lens of focal length 25 cm is placed co-axially in contact with a concave lens of focal length 20 cm . Determine the power of the combination. Will the system be converging or diverging in nature ?

A convex lens of focal length 25 cm is placed co-axially in contact with a concave lens of focal length 20 cm . Determine the power of the combination. Will the system be converging or diverging in nature ?

What is the focal length of a convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm . Is the system a converging or a diverging lens ? Ignore thickness of the lenses.

A converging beam of light is incident on a concave lens of focal length 20 cm. In the absence of the lens, the beam converges at a point 10 m behind the lens. Find where the beam will converge/diverge after refraction.

A convex lens of power 2 D and a concave lens of focal length 40cm are kept in contact, find (a) Power of combination , (b) Equivalent focal length

A convex lens of focal length f_(1) is kept in contact with a concave lens of focal length f_(2) . Find the focal length of the combination.

An eye specialist prescribes spectacles having combination of convex lens of focal length 40cm in contact with a concave lens of focal length 25cm. The power of this lens combination in diopters is

NCERT ENGLISH-LIGHT - REFLECTION AND REFRACTION-Exercise
  1. Find out, from Table 10.3, the medium having highest optical density. ...

    Text Solution

    |

  2. You are given kerosene, turpentine and water. In which of these does t...

    Text Solution

    |

  3. The refractive index of diamond is 2.42. What is the meaning of this s...

    Text Solution

    |

  4. Define one dioptre of power of a lens.

    Text Solution

    |

  5. A convex lens forms a real and inverted image of a needle at a distanc...

    Text Solution

    |

  6. Find the power of a concave lens of focal length 2 m.

    Text Solution

    |

  7. The image formed by a concave mirror is observed to be virtual, erect ...

    Text Solution

    |

  8. Where should an object be placed in front of a convex lens to get a re...

    Text Solution

    |

  9. A spherical mirror and a thin spherical lens each have a focal length ...

    Text Solution

    |

  10. We wish to obtain an erect image of an object, using a concave mirror ...

    Text Solution

    |

  11. Name the type of mirror used in the following situations : (a) Head ...

    Text Solution

    |

  12. One half of a convex lens is covered with a black paper. Will this len...

    Text Solution

    |

  13. An object 5 cm in length is held 25 cm away from a converging lens of ...

    Text Solution

    |

  14. A concave lens has focal length of 15 cm. At what distance should an o...

    Text Solution

    |

  15. An object is placed at a distance of 10 cm from a convex mirror of foc...

    Text Solution

    |

  16. The magnification produced by a plane mirror is m = +1. What does this...

    Text Solution

    |

  17. An object 5.0 cm in length is placed at a distance of 20 cm in front o...

    Text Solution

    |

  18. An object of size 7.0 cm is placed at 27 cm in front of a concave mirr...

    Text Solution

    |

  19. Find the focal length of a lens of power - 2.0 D. What type of lens is...

    Text Solution

    |

  20. A doctor has prescribed lens of power + 1.5 D. Find the focal length o...

    Text Solution

    |