Home
Class 12
PHYSICS
For a normal eye, the cornea of eye prov...

For a normal eye, the cornea of eye provides a converging power of 40D and the least converging power of the eye lens behing the cornea is 20D. Using this information, the distance between the retina and the cornea-eye lends can be estimated to be

A

2.5 cm

B

1.67 cm

C

1.5 cm

D

5 cm

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    AAKASH INSTITUTE ENGLISH|Exercise ASSIGNMENT (SECTION - D)|16 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    AAKASH INSTITUTE ENGLISH|Exercise ASSIGNMENT (SECTION - B)|35 Videos

  • PHYSICAL WORLD

    AAKASH INSTITUTE ENGLISH|Exercise ASSIGNMENT (Section-B)|4 Videos

  • SEMICONDUCTOR ELECTRONICS (MATERIAL, DEVICES AND SIMPLE CIRUITS )

    AAKASH INSTITUTE ENGLISH|Exercise Assignment SECTION - D (Assertion & reason type Question)|10 Videos

Similar Questions

Explore conceptually related problems

For a normal eye, the cornea of eye provides a converging power of 40 D and the least converging power of the eye lens behind the cornea is 20 D . Using this information, the distance between the retina and the cornea eye lens can be estimated to be

For a normal eye, the cornea of eye provides a converging power of 40 D and the least converging power of the eye lens behind the cornea is 20 D . Using this information, the distance between the retina and the cornea eye lens can be estimated to be

A young boy can adjust the power of his eye lens between 50 D and 60 D. His far point is infinity. A. What is the distance of his retina from the eye-lens? b. What is the near point?

The distance of the eye lens from the retina is x. For a normal eye, the maximum focal length of the eye lens

The magnifying power of an astronomical telescope is 8 and the distance between the two lenses is 54 cm. The focal length of eye lens and objective will be respectively.

The power of a lens used by short sighted person, is -2D. Find the maximum distance of an object which he can see without spectacles.

An object is placed at a distance of 30 cm from a converging lens of focal length 15 cm. A normal eye (near point 25 cm, far point infinity) is placed close to the lens on the other side. (a) Can the eye see the object clearly? (b) What should be the minimum separation between the lens and the eye so that the eye can clearly see the object? c. Can a diverging lens, placed in contact with the converging lens, help in seeing the object clearly when the eye is close to the lens?

A normal eye has retina 2 cm behind the eye-lens. What is the power of the eye-lens when the eye is (a) fully relaxed, (b) most strained?

The diameter of the eye ball of a normal eye is about 2.5cm. The power of the eye lens varies from

The ciliary muscles of eye control the curvature of the lens in the eye and hence can alter the effective focal length of the system. When the muscles are fully relaxed, the focal length is maximum. When the muscles are strained, the curvature of lens increases. That means radius of curvature decreases and focal length decreases. For a clear vision, the image must be on the retina. The image distance is therefore fixed for clear vision and it equals the distance of retina from eye lens. It is about 2.5cm for a grown up person. A perosn can theoretically have clear vision of an object situated at any large distance from the eye. The smallest distance at which a person can clearly see is related to minimum possible focal length. The ciliary muscles are most strained in this position. For an average grown up person, minimum distance of the object should be around 25cm. A person suffering from eye defects uses spectacles (eye glass). The function of lens of spectacles is to form the image of the objects within the range in which the person can see clearly. The image o the spectacle lens becomes object for the eye lens and whose image is formed on the retina. The number of spectacle lens used for th eremedy of eye defect is decided by the power fo the lens required and the number of spectacle lens is equal to the numerical value of the power of lens with sign. For example, if power of the lens required is +3D (converging lens of focal length 100//3cm ), then number of lens will be +3 . For all the calculations required, you can use the lens formula and lensmaker's formula. Assume that the eye lens is equiconvex lens. Neglect the distance between the eye lens and the spectacle lens. Q. A far sighted man connot see objects clearly unless they are at least 100cm from his eyes. The number of the spectacle lenses that will make his range of clear vision equal to an average grown up person will be

AAKASH INSTITUTE ENGLISH-RAY OPTICS AND OPTICAL INSTRUMENTS-ASSIGNMENT (SECTION - C)
  1. The angle of a prism is A. One of its refracting surfaces is silvered....

    Text Solution

    |

  2. A plano- convex lens fits exactly into a plano- concave lens. Their pl...

    Text Solution

    |

  3. For a normal eye, the cornea of eye provides a converging power of 40D...

    Text Solution

    |

  4. The magnifying power of a teloscope is 9. When it is adjusted for para...

    Text Solution

    |

  5. A ray of light is incident at small angle I on the surface of prism of...

    Text Solution

    |

  6. A concave mirror of focal length f(1) is placed at a distance of d fro...

    Text Solution

    |

  7. When a biconvex lens of glass having refractive index 1.47 is depped i...

    Text Solution

    |

  8. For the angle of minimum deviation of a prism to be equal to its refra...

    Text Solution

    |

  9. A rod of length 10 cm lies along the principal axis of a concave mirr...

    Text Solution

    |

  10. Which of the following is not due to total internal reflection ?

    Text Solution

    |

  11. A biconvex lens has a radius of curvalure of magnitude 20 cm Which one...

    Text Solution

    |

  12. A converging beam of rays is incident on a diverging lens. Having pass...

    Text Solution

    |

  13. A thin prism of angle 15^(@) made of glass of refractive index mu(1) =...

    Text Solution

    |

  14. A ray of light travelling in a transparent medium of refractive index ...

    Text Solution

    |

  15. A lens having focal length f and aperture of diameter d forms an image...

    Text Solution

    |

  16. The speed of light in media M(1) and M(2) is 1.5xx10^(8) m/s and 2.0x...

    Text Solution

    |

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

    Text Solution

    |

  18. Two thin lenses of focal length f(1) and f(2) are in contact and coaxi...

    Text Solution

    |

  19. A boy is trying to start a fire by focusing sunlight on a piece of pap...

    Text Solution

    |

  20. The frequence of a light wave in a material in 2xx10^(14) Hz and wavel...

    Text Solution

    |