Home
Class 12
PHYSICS
The radii of curvature of the surfaces o...

The radii of curvature of the surfaces of a double convex lens are `20 cm and 30 cm`. What will be its focal length and power in air and water respectively ? Refractive indices for glass and water are `3//2 and 4//3` respectively.

Text Solution

Verified by Experts

The correct Answer is:
`24 cm, 4.17 D`; `96 cm, 1.04 D`
Promotional Banner

Topper's Solved these Questions

  • OPTICS

    PRADEEP|Exercise Problems for practice|4 Videos

  • OPTICS

    PRADEEP|Exercise Comprehension 1|1 Videos

  • OPTICS

    PRADEEP|Exercise Value based questions|3 Videos

  • MAGNETIC EFFECT OF CURRENT AND MAGNETISM

    PRADEEP|Exercise Competition Focus (Multiple Choice Questions)|2 Videos

Similar Questions

Explore conceptually related problems

The radii of curvature of the surfaces of a double convex lens are 20 cm and 40 cm respectively, and its focal length is 20 cm . What is the refractive index of the material of the lens ?

The radii of curvatures of a double convex lens are 15 cm and 30 cm, and its refractive index is 1.5. Then its focal length is -

The radii of curvature of a double concave lens are 30 cm and 45 cm. What is its focal length in water ? [""_(a)n_(g)=1.5, ""_(a)n_(w)=4//3]

The radii of curvature of a double convex lens are 30 cm and 60 cm and its refractive index is 1.5. calculate its focal length.

The radii of curavture of surfaces of a convex lens of glass are 20 cm each. If mu is glass is 3//2 , power of lens in diopter is.

The radii of curvature of the two surface of a double convex glass lens are 10 cm and 20 cm respectively. If the refractive index of glass in 1.5, then its focal length will be

The radii of curvature of the faces of a double convex lens are 10 cm and 20. The refractive index of the glass is 1.5. What is the power of this lens (in units of dioptre)?

(i) If f = + 0.5 m , what is the power of the lens ? (ii) The radii of curvature of the faces of a double convex lens are 9 cm and 15 cm . Its focal length is 12 cm . What is the refractive index of glass ? (iii) A convex lens has 20 cm focal length in air. What is the focal length in water ? (Refractive index of air-water = 1.33 , refractive index of air-glass = 1.5 ).

If the radii of curvature of the two surfaces of a concave lens are 10 cm and 20 cm respectively and the refractive index is 1.5. What is its focal length ?

PRADEEP-OPTICS-Exercise
  1. A convex lens made up of glass of refractive index 1.5 is dippedin tur...

    Text Solution

    |

  2. A converging lens of refractive index 1.5 and of focal length 15 cm in...

    Text Solution

    |

  3. The radii of curvature of the surfaces of a double convex lens are 20 ...

    Text Solution

    |

  4. A convex lens made up of glass of refractive index 1.5 is dippedin tur...

    Text Solution

    |

  5. A biconvex lens is made of glass with mu = 1.52. Each surface has a ra...

    Text Solution

    |

  6. A concave lens has same radii of curvature for both sides and is made ...

    Text Solution

    |

  7. A double convex lens of glass of refractive index 1.6 has its both sur...

    Text Solution

    |

  8. Convex lens is made of glass of refractive index 1.5 If the radius of ...

    Text Solution

    |

  9. A glass convex lens has a power of + 10 D . When this lens is totally ...

    Text Solution

    |

  10. A convex lens of focal length 20 cm and made of glass (mu = 1.5) is im...

    Text Solution

    |

  11. A thin converging lens made of glass of refractive index 1.5 acts as a...

    Text Solution

    |

  12. Find the radius of curvature of convex surface of a plano convex lens,...

    Text Solution

    |

  13. A corverging lens has a focal length of 20 cm in air. It is made of a ...

    Text Solution

    |

  14. A converging lens of refractive index 1.5 and of focal length 15 cm in...

    Text Solution

    |

  15. From the ray diagram shown in Fig. calculte the focal length of concav...

    Text Solution

    |

  16. A convex lens is used to throw on a screen 10 m from the lens, a magni...

    Text Solution

    |

  17. An object is placed at a distance of 1.5 m from a screen and a convex ...

    Text Solution

    |

  18. A screen is placed 80 cm from an object. The image of the object on th...

    Text Solution

    |

  19. A convergent beam of light passes through a diverging lens of focal le...

    Text Solution

    |

  20. The image obtained with a convex lens is erect and its length is 4 tim...

    Text Solution

    |