Home
Class 11
PHYSICS
Assuming the sun to have a spherical out...

Assuming the sun to have a spherical outer surface of radiating like a black body at temperature `t^@C`, the power received by a unit surface,(normal to the incident rays) at a distance R from the centre of the sun is

A

`r^2sigma (t + 273)^4//R^2`

B

`4pir^2sigmat^4//R^2`

C

`r^2sigma (t+ 273)^4//4piR^2`

D

`16pi^2r^2sigmat^4//R^2`

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • BULK MATTER

    SARAS PUBLICATION|Exercise EXAMPLE|43 Videos

  • KINEMATICS

    SARAS PUBLICATION|Exercise EXAMPLE|23 Videos

Similar Questions

Explore conceptually related problems

Assume that a tunnel ils dug along a chord of the earth, at a perpendicular distance R/2 from the earth's centre where R is the radius of the earth. The wall of the tunnel is frictionless. a. Find the gravitational force exerted by the earth on a particle of mass m placed in the tunnel at a distance x from the centre of the tunnel. b. Find the component of this fore along the tunnel and perpendicular to the tunnel. c. Find the normal force exerted by the wall on the particle. d. Find the resultant force on the particle. e.Show that the motion of the particle in the tunnel is simple harmonic and find the time period.

Find the fluz f the electric field through a spherical surface of radius R due to a charge of 10^(-7) C at the centre and another equal charge at a point 2R away from the centre (figure ).

When the sun is directly overhead, the surface of the earth receives 1.4 xx (10^3) W (m^-2) of sunlight. Assume that the light is monochromatic with average wavelength 500mn and that no light is absorbed in between the sun and the earth's surface. The distance between the sun and the earth is 1.5 xx (10^11) m. (a) Calculate the number of photons falling per second on each square metre of earth's surface directly below the sun. (b) How many photons are there in each cubic metre near the earth's surface at any instant? (c) How many photons does the sun emit per second?

Two bodies A and B having equal surface areas are maintained at temperatures 10^(@)C . And 20^(@)C . The thermal radiation emitted in a given time by A and B are in the ratio

A concave mirror of radius of curvature 60 cm is placed at the bottom and height of 20 cm. The mirror faces upwards with its axis vertical. Solar light fall normally on the surface of water and image of sun is formed. If a mu_omega = 4/3 then will the observer in air, the distance of image from the surface of water is

Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates .Most of the energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10kg water and 0.2g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decreases by 5^(@)C . Specific heat capacity of water = 4200J kg^(-1).^@C^(-1) and latent heat of vaporization of water = 2.27 xx 10^(6)J kg^(-1)

The light from the sun is found to have a maximum intensity near the wavelength of 470nm. Assuming that the surface o f the sun emits as a blackbody, calculate the temperature of the surface of the sun.

The constant A in the Richardson-Dushman equation for tungsten is 60 xx 10^(4) A m^(-2) . The work function of tungsten is 4.5 eV . A tungsten cathode having a surface area 2.0 xx 10^(-5) m^2 is heated by a 24 W electric heater. In steady state, the heat radiated by the cathode equals the energy input by the heater and the temperature becomes constant. Assuming that the cathode radiates like a blackbody, calculate the saturation current due to thermions. Take Stefan constant = 6 xx 10^(-8) W m^(-2) K^(-4) . Assume that the thermions take only a small fraction of the heat supplied.

SARAS PUBLICATION-GRAVITATION-EXAMPLE
  1. Assuming the sun to have a spherical outer surface of radiating like a...

    Text Solution

    |

  2. A shell of mass 200 gm is ejected from a gun of mass 4 kg by an explos...

    Text Solution

    |

  3. A body of mass 1 kg is thrown upwards with a velocity 20 ms^(-1). It m...

    Text Solution

    |

  4. A particle has an initial velocity 3 \hat { i } + 4 \hat { j } and an ...

    Text Solution

    |

  5. A particle moves a distance x in time t according to equation x=(t+5)^...

    Text Solution

    |

  6. A man of 50 kg mass is standing in a gravity free space at a height of...

    Text Solution

    |

  7. A person of mass 60 kg is inside a lift of mass 940kg and presses the ...

    Text Solution

    |

  8. A body projected electrically from the earth reaches a height equal to...

    Text Solution

    |

  9. A particle moves in a circle of radius 5 cm with constant speed and ti...

    Text Solution

    |

  10. A planet moving along an elliptical orbit is closest to the Sun at dis...

    Text Solution

    |

  11. A body is moving with velocity 30m//s towards east .After 10 seconds i...

    Text Solution

    |

  12. The height at which the weight of a body becomes 1//16 th its weight o...

    Text Solution

    |

  13. A geostationary satellite is orbiting the earth at a height of 5R abov...

    Text Solution

    |

  14. A spherical planet has a mass M(p) and diameter D(p). A particle of ma...

    Text Solution

    |

  15. When a biconvex lens of glass having refractive index 1.47 is dipped i...

    Text Solution

    |

  16. An infinite number of bodies, each of mass 2 kg, are situated on at di...

    Text Solution

    |

  17. Calculate the ratio of radii of gyration of a circular ring and dise o...

    Text Solution

    |

  18. A planet has the radius twice that of earth and has same density as th...

    Text Solution

    |

  19. A particle of mass 'm' is kept at rest at a height 3R from the surface...

    Text Solution

    |

  20. The ratio of the acceleration for a solid sphere (mass m and radius R)...

    Text Solution

    |