Home
Class 12
PHYSICS
A convex lens of focal length 80 cm and ...

A convex lens of focal length 80 cm and a concave lens of focal length 50 cm are combined toghether. What will be their resulting power ?

A

`+7.5D`

B

`-0.75D`

C

`+6.5D`

D

`-6.5D`

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

A convex lens of focal length 20 cm and a concave lens of focal length 10 cm are placed 20 cm apart. In between them an object placed at distance x from the convex lens. What will be the linear magnification produced convex lens and concave lens individually ?

A convex lens of focal length 20 cm and a concave lens of focal length 10 cm are placed 20 cm apart. In between them an object placed at distance x from the convex lens. What is the value of x (in cm ) so that images from by both the lenses coincides ?

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

An achromatic lens-doublet is formed by placing in contact a convex lens of focal length 20 cm and a concave lens of focal length 30 cm. The dispersive power of the material of the convex lens is 0.8. Determine the dispersive power of the material of the concave lens. Calculate the focal length of the lens-doublet.

A convex lens A of focal length 20cm and a concave lens B of focal length 10 cm are kept along the same axis with a distance d between them. If a parallel beam, then d is

A convex lens A of focal length 20cm and a concave lens B of focal length 10 cm are kept along the same axis with a distance d between them. If a parallel beam, then d is

A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. The power of the combination is

A convex lens of focal length A and a concave lens of focal length B are placed in contact. The focal length of the combination is

A convex lens of focal length 20cm is placed 10cm away from a second convex lens of focal length 25 cm. What wil be the location of the image of an object at 30 cm in front of the first lens?

A convex lens of focal length 20cm and a concave lens of focal length f are mounted coaxially 5cm apart. Parallel beam of light incident on the convex lens emerges from the concave lens as a parallel beam. Then, f in cm is

AAKASH INSTITUTE ENGLISH-RAY OPTICS AND OPTICAL INSTRUMENTS-ASSIGNMENT (SECTION - C)
  1. Alens is placed between a source of light and a wall. It forms images ...

    Text Solution

    |

  2. If f(V) and f(R) are the focal lengths of a convex lens for violet and...

    Text Solution

    |

  3. A convex lens of focal length 80 cm and a concave lens of focal length...

    Text Solution

    |

  4. The focal lengths of a converging lens measured for violet, green and ...

    Text Solution

    |

  5. A luminous object is placed at a distance of 30 cm. from the convex le...

    Text Solution

    |

  6. A plano convex lens is made of material of refactive index 1.6 The rad...

    Text Solution

    |

  7. For a plane convex lens (mu = 1.5) has radius of curvature 10 cm. It i...

    Text Solution

    |

  8. A bubble in glass slab (mu = 1.5) when viewed from one side appears at...

    Text Solution

    |

  9. A body is locatyed on a wall. Its image of equal size is to be obtaine...

    Text Solution

    |

  10. A convex lens is dipped in a liquid whose refractive index is equal t...

    Text Solution

    |

  11. An equiconvex lens in cut into two halves along (i) XOX' f,f',f'' be t...

    Text Solution

    |

  12. Which of the following is incorrect?

    Text Solution

    |

  13. A double concave thin lens made out of glass (mu=1.5) have radii of cu...

    Text Solution

    |

  14. A convex lens forms a real image 16 mm long on a screen. If the lens i...

    Text Solution

    |

  15. A point object is moving with speed u(0) at a position somewhere betwe...

    Text Solution

    |

  16. The minimum magnifying power of an astronomial telescope is M. If the ...

    Text Solution

    |

  17. An object is placed in front of two convex lenses one by one at a dist...

    Text Solution

    |

  18. If R(1)andR(2) are the radii of curvature of the spherical surfaces of...

    Text Solution

    |

  19. The focal length of a thin lens in vacuum is f. If the material of the...

    Text Solution

    |

  20. An astronomical telescope of ten-fold angular magnification has a leng...

    Text Solution

    |