Home
Class 12
PHYSICS
A far-sighted man can see clearly at a d...

A far-sighted man can see clearly at a distance of `1.0m`. The power of the lens that would make him see clearly at a distance of `0.2m` is

A

`4 D`

B

`-4 D`

C

`6 D`

D

`-6 D`

Text Solution

Verified by Experts

The correct Answer is:
A
`(1)/(-(N.P.)) - (1)/(-("distance of object")) = (1)/(f)`
`(1)/(-1.0)-(1)/(-0.2) =- 1+5 = (1)/(f) rArr (1)/(f) = P = 4D`
Promotional Banner

Topper's Solved these Questions

  • OPTICAL INSTRUMENTS

    CP SINGH|Exercise EXERCISES|63 Videos

  • NUCLEAR PHYSICS AND RADIO ACTIVITY

    CP SINGH|Exercise EXERCISES|118 Videos

  • PHOTOELECTRIC EFFECT

    CP SINGH|Exercise EXERCISES|73 Videos

Similar Questions

Explore conceptually related problems

A person can see clearly upto 1 m. The nature and power of the lens which will enable him to see things at a distance of 3 m is

A person who can see things most clearly at a distance of 10 cm . Requires spectacles to enable to him to see clearly things at a distance of 30 cm. What should be the focal length of the spectacles ?

A nearsighted man can clearly see objects up to a distance of 1.5m. Calculate the power of the lens of the spectacles necessary for the remedy of this defect.

If a person can sees clearly at a distance of 100 cm, then find the power of leris used to see object at 40 cm.

A nearsighted person cannot clearly see beyond 200 cm. Find the power of the lens needed to see objects at large distances.

A far sighted person has his near point 50 cm. Find the power of lens he should use to see at 25 cm, clearly.

(a) A nearsighted person cannot clearly see beyond 200 cm . Find the power of the lens needed to see objectes at large distances. (b) A farsighted person cannot see objects placed closer to 50cm . Find the power of the lens needed to see the objets at 20cm . (c) A person wears glasses of power -2.5 D . Is the person farsighted or nearsighted? What is the far point of the person without the glasses?

CP SINGH-OPTICAL INSTRUMENTS-EXERCISES
  1. 1. Identify the wrong description of the above figures

    Text Solution

    |

  2. Mark the correct options (i) If the far point goes ahead, the power ...

    Text Solution

    |

  3. In the case of hypermetropia (i) the image of a near object is forme...

    Text Solution

    |

  4. Astigmatism for a human eye can be removed by using

    Text Solution

    |

  5. A man, wearing glasses of power +2D can read clearly a book placed at ...

    Text Solution

    |

  6. A person whose far-point is at 30cm wants to read at 50cm. The power o...

    Text Solution

    |

  7. A person wears glasses of power -2.5D. The defect of the eye and the f...

    Text Solution

    |

  8. A far-sighted man can see clearly at a distance of 1.0m. The power of ...

    Text Solution

    |

  9. The near point of a person is 50 cm and the far point is 1.5m. The spe...

    Text Solution

    |

  10. An eye specialist prescribes spectacles having combination of convex l...

    Text Solution

    |

  11. How should people wearing spectacles work with a microscope

    Text Solution

    |

  12. Chromatic aberrations in the formation of image by a lens arise becaus...

    Text Solution

    |

  13. Which of the following quantities related to a lens depend on the wave...

    Text Solution

    |

  14. Let f(v) and f(r) are the focal lengths of a convex lens for violet an...

    Text Solution

    |

  15. An achromaic convergent system of focal length +20cm is made of two le...

    Text Solution

    |

  16. A combination of two thin lenses of the same material with focal lengt...

    Text Solution

    |

  17. The dispersive powers of crown and flint glasses are 0.02 and 0.04 res...

    Text Solution

    |

  18. The dispersive power of the material of lens of focal length 20cm is 0...

    Text Solution

    |

  19. Spherical aberration in a thin lens can be reduced by

    Text Solution

    |

  20. Spherical aberration in a lens

    Text Solution

    |