Home
Class 12
PHYSICS
A small source of light is to be suspend...

A small source of light is to be suspended directly above the centre of a circular table of radius R . What should be the height of the light source above the table so that the intensity of light is maximum at the edges of the table compared to any other height of the source

A

`(R)/(2)`

B

`(R)/(sqrt2)`

C

`R`

D

`sqrt2 R`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS

    ERRORLESS |Exercise Refraction of Light at Plane Surfaces|9 Videos

  • RAY OPTICS

    ERRORLESS |Exercise Refraction at Curved Surface|8 Videos

  • MAGNETISM

    ERRORLESS |Exercise Assertion & Reason|1 Videos

  • WAVE OPTICS

    ERRORLESS |Exercise SET|23 Videos

Similar Questions

Explore conceptually related problems

A lamp is hanging along the axis of a circular table of radius r. at what height should the lamp be placed above the table so that the intensity of illumination at the edge of the table is (1)/(8) of that at its centre ?

An isotropoic point source of light is suspeneded h metre vericlaly above the centre of circular table of radius r metre.Then the ratio of illumenances at the centre to that at the edge of the table is

An electric bulb is hanging above the centre of a circular table of radiys 3m at a height of 3m from the its centre. Find the ratio of illuminance at the centre and at a point on the edge of the table.

A student is studying a book placed near the edge of a circular table of radius R. A point source of light is suspended directly above the centre of the table. What should be the height of the source above the table so as to produce maximum illuminance at the position of the book ?

At what height should a lamp be hung above the centre of a round table of radius R to otain the maximum illumination at its edges?

If anelectric lamp be suspended at a height h from a circular table of radius r, prove that the intensity of illumination at thecentre of the table is (1+(r^(2))/(h^(2)))^(3//2) times that at the edge of the table.

A lamp of 120 candela hangs at a height of 4 m excathy above the centre of a circular table of diameter of 6.m Caluclate the illuminance at the centre and at the edge of the table.

A bulb of 100 watt is hanging at a height of one meter above the centre of a circular table of diameter 4 m . If the intensity at a point on its rim is I_(0) , then the intensity at the centre of the table will be

ERRORLESS -RAY OPTICS-SET
  1. A small source of light is to be suspended directly above the centre o...

    Text Solution

    |

  2. In an astronomical telescope in normal adjustment a straight black lin...

    Text Solution

    |

  3. Three lenses L(1) , L(2) , L(3) are placed co-axially as shown in figu...

    Text Solution

    |

  4. An object is placed at a point distant x from the focus of a convex le...

    Text Solution

    |

  5. The diameter of the eye-ball of a normal eye is about 2.5 cm . The pow...

    Text Solution

    |

  6. In a thin spherical fish bowl of radius 10 cm filled with water of ref...

    Text Solution

    |

  7. A small fish 0.4 m below the surface of a lake is viewed through a sim...

    Text Solution

    |

  8. A water drop in air refractes the light ray as

    Text Solution

    |

  9. Which of the following ray diagram show physically possible refraction...

    Text Solution

    |

  10. Following figure shows the multiple reflections of a light ray along a...

    Text Solution

    |

  11. When the rectangular metal tank is filled to the top with an unknown l...

    Text Solution

    |

  12. A concave mirror and a converging lens (glass with mu = 1.5) both have...

    Text Solution

    |

  13. A ray of light strikes a plane mirror M at an angle of 45^(@) as shown...

    Text Solution

    |

  14. A slab of glass, of thickness 6 cm and refractive index 1.5, is placed...

    Text Solution

    |

  15. A point source of light S is placed at the bottom of a vessel containi...

    Text Solution

    |

  16. A point object is placed midway between two plane mirrors a distance a...

    Text Solution

    |

  17. A convergent beam of light is incident on a convex mirror so as to con...

    Text Solution

    |

  18. PQR is a right angled prism with other angles as 60^(@) and 30^(@). Re...

    Text Solution

    |

  19. When a ray is refracted from one medium to another, the wavelength cha...

    Text Solution

    |

  20. Two this lenses, when in contact, produce a combination of power +10 d...

    Text Solution

    |

  21. The plane faces of two identical plano convex lenses, each with focal ...

    Text Solution

    |