Home
Class 12
PHYSICS
Three lenses in contact have a combined ...

Three lenses in contact have a combined focal length of 12 cm. When the third lens is removed, the combined focal length is `(60)/(7)` cm. The third lens is

A

A converging lens of focal length 30 cm

B

A converging lens of foca length 60 cm

C

A diverging lens of focal length 30 cm

D

A diverging lens of focal length 60 cm

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    AAKASH INSTITUTE|Exercise Assignment (Section - B) Objective Type Questions (One option is correct)|16 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    AAKASH INSTITUTE|Exercise Assignment (Section - C) Objective Type Questions (More than one option are correct)|10 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

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

  • PHYSICAL WORLD

    AAKASH INSTITUTE|Exercise ASSIGNMENT (Section-B)|5 Videos

  • SEMICONDUCTOR ELECTRONICS (MATERIAL, DEVICES AND SIMPLE CIRUITS )

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

Similar Questions

Explore conceptually related problems

Two thin lenses, one of focal length + 60 cm and the other of focal length – 20 cm are put in contact. The combined focal length is

Two thin lenses, aone convex of focal length 10 cm and other concave lens are kept in contact to form a composite lens of focal length 13 cm . If the combination acts as a converging lense the focal length of second lens is

We combined a convex lens of focal length f_(1) and concave lens of focal lengths f_(2) and their combined focal length was F . The combination of these lenses will behave like a concave lens, if

A concave lens is kept in contact with convex lens of focal length 20 cm. The combination works as a convex lens of focal length 50 cm. Find the power of concave lens.

An object is placed at a distance of 10cm form a co-axial combination of two lenses A and B in contact. The combination forms a real image three times the size of the object. If lens B is concave with a focal length of 30cm. The nature and focal length of lens A is

Power (P) of a lens is given by reciprocal of focal length (f) of the lens. i.e. P = 1//f . When f is in metre, P is in dioptre. For a convex lens, power is positive and for a concave lens, power is negative. When a number of thin lenses of powers p_(1), p_(2), p_(3).... are held in contact with one another, the power of the combination is given by algebraic sum of the powers of all the lenses i.e., P = p_(1) + p_(2) + p_(3) + ........ Answer the following questions : Two thin lenses are in contact and the focal length of the combination is 80 cm . If the focal length of one lens is 20 cm , the focal length of the other would be

Two convex lenses of focal length 10 cm each are combined. What will be the focal length of the combined lens ?

A concave lens is kept in contact with a convex lens of focal length 20 cm . The combination works as a converging lens of focal length 100 cm . Calculate power of concave lens.

A convex lens of power +2.5 D is in contact with a concave lens of focal length 25 cm. The power of combination is

AAKASH INSTITUTE-RAY OPTICS AND OPTICAL INSTRUMENTS-Assignment (Section - A) Objective Type Questions (One option is correct)
  1. A parallel beam of monochromatic light falls on a combination of a con...

    Text Solution

    |

  2. The magnifications produced by a convex lens for two different positio...

    Text Solution

    |

  3. Three lenses in contact have a combined focal length of 12 cm. When th...

    Text Solution

    |

  4. A lens made of material of Refractive index mu(2) is surrounded by a m...

    Text Solution

    |

  5. The radii of curvatures of a convex lens are 0.04 m and 0.04m. Its ref...

    Text Solution

    |

  6. For a plano convex lens, the radius of curvature of convex surface is ...

    Text Solution

    |

  7. A convex glass lens (mu(g) = 1.5) has a focal length of 8 cm when plac...

    Text Solution

    |

  8. A light ray is incident normally on one of the refracting faces of a p...

    Text Solution

    |

  9. If a light ray incidents normally on one of the faces of the prism of ...

    Text Solution

    |

  10. A ray of light is incident on one of the faces of the angle prism with...

    Text Solution

    |

  11. A prism of refractive index sqrt(2) has a refracting angle of 60^(@). ...

    Text Solution

    |

  12. The least angle of deviation for a glass prism is equal to its refract...

    Text Solution

    |

  13. A light ray of angles of incidence 40^(@) emerged from the prism in mi...

    Text Solution

    |

  14. The angle of minimum deviation for a 75^(@) prism of dense glass is fo...

    Text Solution

    |

  15. Suppose a small angled prism of 6^(@) deviates a ray through 3^(@), th...

    Text Solution

    |

  16. A crown glass prism of angle of 5^@ is to be combined with a flint gla...

    Text Solution

    |

  17. A thin prism of angle 6^(@) made up of glass of refractive index 1.5 i...

    Text Solution

    |

  18. Compare the dispersive powers of two prisms if one of them deviates th...

    Text Solution

    |

  19. A convex mirror forms an image one-fourth the size of the object. If o...

    Text Solution

    |

  20. A microscope is focussed on the scratch at the bottom of a beaker. Wat...

    Text Solution

    |