Home
Class 12
PHYSICS
What is meant by power of a lens? What d...

What is meant by power of a lens? What does its sign indicate? State it SI unit, how is it related to the focal length of a lens?

Text Solution

Verified by Experts

Power of a lens: It is defined as the reciprocal of focal length (in metres) of a lens.
`P=1/(f("in m"))`
S.I. unitof power of a lens is dioptre (D).
One dioptre: If a lens has a focal length one metre then its power is said to be one dioptre.
Promotional Banner

Topper's Solved these Questions

  • REFRACTION OF LIGHT

    BETTER CHOICE PUBLICATION|Exercise LONG ANSWER TYPE QUESTIONS|9 Videos

  • REFRACTION OF LIGHT

    BETTER CHOICE PUBLICATION|Exercise NUMERICAL PROBLEMS|36 Videos

  • REFRACTION OF LIGHT

    BETTER CHOICE PUBLICATION|Exercise MOST EXPECTED QUESTIONS|2 Videos

  • REFLECTION OF LIGHT

    BETTER CHOICE PUBLICATION|Exercise NUMERICALS PROBLEMS|7 Videos

  • SEMI CONDUCTOR DEVICES

    BETTER CHOICE PUBLICATION|Exercise Most Expected Questions|6 Videos

Similar Questions

Explore conceptually related problems

What is meant by power of lens? What is SI units? Define one dioptre.

What is meant by electric power ? Give its SI unit.

What is the SI unit of power ?

What is meant by magnetic flux? State its S.I. unit.

Define power of lens and give its units.

What is meant by resistivity ? Write its S.I. unit.

BETTER CHOICE PUBLICATION-REFRACTION OF LIGHT-SHORT ANSWER TYPE QUESTIONS
  1. What is meant by power of a lens? What does its sign indicate? State i...

    Text Solution

    |

  2. Why diamond is hard while graphite is soft ?

    Text Solution

    |

  3. Write the conditions for total internal reflection to takeplace?

    Text Solution

    |

  4. How will you explain twinkling of stars?

    Text Solution

    |

  5. When does snell's law in refraction fails?

    Text Solution

    |

  6. The sun appears red at sun rise or sunset, why?

    Text Solution

    |

  7. A concave mirror and a convex lens are held separetly in water. What c...

    Text Solution

    |

  8. Answer the following questions: A diver under water, looks obliquely ...

    Text Solution

    |

  9. Write the conditions for total internal reflection to takeplace?

    Text Solution

    |

  10. Derive the expression for the power of two thin lenses placed in conta...

    Text Solution

    |

  11. Explain total internal reflection. What are its conditions?

    Text Solution

    |

  12. Prove the relation ""^(a)mu(b)=1/(""^(b)mu(a))

    Text Solution

    |

  13. State generalized Snell's law of refraction through multiple parallel ...

    Text Solution

    |

  14. Explain total internal reflection. What are its conditions?

    Text Solution

    |

  15. Write the conditions for total internal reflection to takeplace?

    Text Solution

    |

  16. State the condition of total internal reflection. Calculate the speed...

    Text Solution

    |

  17. What are opiates? Give their functions.

    Text Solution

    |

  18. What is the relation between critical angle and refractive index? What...

    Text Solution

    |

  19. What are the uses of optical fibre?

    Text Solution

    |