Home
Class 12
PHYSICS
A biconvex of focal length forms a circ...

A biconvex of focal length forms a circular image of radius r of sun in focal plane.Then,which option is correct?

A

`pi r^2 00 f^2`

B

`pi r^2 00f^2`

C

If lower half part is covered by blasck sheet,then area of the image is `pi r^2//2`.

D

If f is doubled ,intensity will increase.

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • UNIT TEST -06

    MODERN PUBLICATION|Exercise EXERCISE|461 Videos

  • TEXUAL QUESTIONS

    MODERN PUBLICATION|Exercise EXERCISE|195 Videos

  • UNIT TEST -07

    MODERN PUBLICATION|Exercise EXERCISE|154 Videos

Similar Questions

Explore conceptually related problems

What is the focal length of a plane mirror ?

Find the focal length of convex mirror whose radius of curvature is 32 cm.

A biconvex lens of focal length 15 cm is in front of a plane mirror.The distnace betweent the lens and the mirror is 10 cm.A small object is kept at a distance of 30 cm from the lens .The final image is

The size of the image of an object,which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the image

MODERN PUBLICATION-UNIT TEST -06-EXERCISE
  1. A convex lens is in contact with concave lens .The magnitude of the ra...

    Text Solution

    |

  2. A hollow doublew concave lens is made of very thin transparent materia...

    Text Solution

    |

  3. A biconvex of focal length forms a circular image of radius r of sun ...

    Text Solution

    |

  4. A real image of a distant object is formed by a plano-convex lens on i...

    Text Solution

    |

  5. A ray of light passes through an equilateral glass prism,such that ang...

    Text Solution

    |

  6. A ray of light is incident on an equilateral glass prism placed on a h...

    Text Solution

    |

  7. A given ray of light suffers minimum deviation in an equilateral prism...

    Text Solution

    |

  8. A thin prism of angle 15^@ made of glass of refractive index = 1.5 is...

    Text Solution

    |

  9. White ligth is incident on the interface of glass and air as shown in ...

    Text Solution

    |

  10. A beam of light consisting of red, green and blue and is incident on a...

    Text Solution

    |

  11. Which one of the following spherical lenses does not exhibit dispersio...

    Text Solution

    |

  12. In a compound microscope,the intermediate image is

    Text Solution

    |

  13. The focal length of the objective of a microscope is

    Text Solution

    |

  14. When the length of a microscope tube is increased,its magnifying power

    Text Solution

    |

  15. The 'f number' of a given camera is 8.It means that

    Text Solution

    |

  16. The interfernce phenomenon can take place

    Text Solution

    |

  17. Two waves of intensities I and 4 I superimpose, then maximum and minim...

    Text Solution

    |

  18. Two beams of light having intensities I and 4 I interfere to produce a...

    Text Solution

    |

  19. The contrast in the fringes in any interference pattern depends on

    Text Solution

    |

  20. For constructive interfrence to take place between two monochromatic l...

    Text Solution

    |