Home
Class 10
PHYSICS
A doctor has prescribed lens of power + ...

A doctor has prescribed lens of power `+ 1.5 D`. Find the focal length of the lens. Is the prescribed lens diverging or converging ?

Text Solution

Verified by Experts

The power of this lens is lens is positive (with a plus sign), therefore, this is a convex lens or converging lens. Now,
`"Power, "P=1/(f("in metres"))`
`"So, "+1.5=1/f`
`"or "f = 1/(+1.5)m`
`f = + 1/(1.5)xx100 cm`
So, Focal length of lens, f= + 66.7 cm
Promotional Banner

Topper's Solved these Questions

  • REFLECTION OF LIGHT

    LAKHMIR SINGH & MANJIT KAUR|Exercise Multiple Choice Questions (MCQs)|1 Videos

  • REFLECTION OF LIGHT

    LAKHMIR SINGH & MANJIT KAUR|Exercise Very Short Answer Type Questions|1 Videos

  • REFLECTION OF LIGHT

    LAKHMIR SINGH & MANJIT KAUR|Exercise Very Short Answer Type Questions|1 Videos

  • MAGNETIC EFFECT OF ELECTRIC CURRENT

    LAKHMIR SINGH & MANJIT KAUR|Exercise NCERT BOOK|2 Videos

  • REFRACTION OF LIGHT

    LAKHMIR SINGH & MANJIT KAUR|Exercise VERY SHORT ANSWER TYPE QUESTIONS|1 Videos

Similar Questions

Explore conceptually related problems

A doctor has prescribed a corrective lens of power, -1.5D . Find the focal length of the lens. Is the prescribed lens diverging or converging?

Find the focal length of a lens having -0.5 D power.

Doctor has presecribed a lens having power + 1.5D. What will be the focal length of the lens ? What is the type of the lens and what must be the defect of vision ?

If a spherical lens has a power of, -0.25 D, the focal length of this lens will be:

LAKHMIR SINGH & MANJIT KAUR-REFLECTION OF LIGHT -Exercise
  1. Define one dioptre of power of a lens.

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

  4. Which one of the following materials cannot be used to make a lens ?

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

  8. No matter how far you stand from a spherical mirror, your image appear...

    Text Solution

    |

  9. Which of the following lenses would you prefer to use while reading sm...

    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 convcave lens of focal length 15 cm forms an image 10 cm from the le...

    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

    |