Home
Class 11
PHYSICS
Assume that the total surface area of a ...

Assume that the total surface area of a human body is `1.6m^(2)` and that it radiates like an ideal radiator. Calculate the amount of energy radiates per second by the body if the body temperature is `37^(@)C` . Stefan constant `sigma` is `6.0xx10^(-8)Wm^(-2)K^(-4)` .

Text Solution

Verified by Experts

The correct Answer is:
`887 J`
`A = 1.6m^(1) e = 1`
`(dQ)/(dt) = p sigmaeA T^(4) =(6 xx 10^(-8)) (1) 1.6 m^(2) (310)^(4)`
`= 887 J`
Promotional Banner

Topper's Solved these Questions

  • HEAT TRANSFER

    RESONANCE ENGLISH|Exercise Exercise-3|1 Videos

  • GRAVITATION

    RESONANCE ENGLISH|Exercise Exercise|21 Videos

  • KINEMATICS

    RESONANCE ENGLISH|Exercise Exercise|65 Videos

Similar Questions

Explore conceptually related problems

Calculate the amount of radiant energy from a black body at a temperature of (i) 27^(@) C (ii) 2727^(@) C. sigma = 5.67xx10^(-8)Wm^(-2)K^(-4) .

Calculate the temperature at which a perfect black body radiates at the rate of 1 W cm^(-2) , value of Stefan's constant, sigma = 5.67 xx 10^(-5) W m^(-2) K^(-8)

Calculate the energy radiated per minute by a black body of surface area 200 cm^(2) , maintained at 127^(@) C. sigma = 5.7xx10^(-8)Wm^(-2)K^(-4)

The earth receives solor radiation at a rate of 8.2Jcm^(-2)min^(-1) . Assuming that the sun radiates like a blackbody, calculate the surface temperature of the sun. The angle subtended by the sun on the earth is 0.53^(@) and the stefan constant sigma=5.67xx10^(-s)Wm^(-2)K^(-4) .

Calculate the wavelength at which a hot body radiates maximum energy if its surface temperature is 3200^(@) C. Wien's constant 0.00289 mK.

Calculate the amount of heat radiated per second by a body of surface area 12cm^(2) kept in thermal equilibrium in a room at temperature 20^(@)C The emissivity of the surface =0.80 and sigma=6.0xx10^(-s)Wm^(-2)K^(-4) .

One end of a rod of length 20cm is inserted in a furnace at 800K The sides of the rod are covered with an insulating material and the other end emits radiation like a black body. The temperature of this end is 750K in the steady state The temperature of the surrounding air is 300K Assuming radiation to be the only important mode of energy transfer between the surrounding and the open end of the rod, find the thermal conductivity of the rod Stefan's constant sigma = 6.0 xx 10^(-8) W m^(-2) K^(-4) .

One end of a rod length 20cm is inserted in a furnace at 800K. The sides of the rod are covered with an insulating material and the other end emits radiation like a blackbody. The temperature of this end is 750K in the steady state. The temperature of the surrounding air is 300K. Assuming radiation to be the only important mode of energy transfer between the surrounding and the open end of the rod, find the thermal conductivity of the rod. Stefan constant sigma=6.0xx10^(-1)Wm^(-2)K^(-4) .

One end of a rod length 20cm is inserted in a furnace at 800K . The sides of the rod are covered with an insulating material and the other end emits radiation like a blackbody. The temperature of this end is 750K in the steady state. The temperature of the surrounding air is 300K . Assuming radiation to be the only important mode of energy transfer between the surrounding and the open end of the rod, find the thermal conductivity of the rod. Stefan constant sigma=6.0xx10^(-1)Wm^(-2)K^(-4) .

A spherical ball of surface area 20cm^(2) absorbs any radiation that falls on it. It is suspended in a closed box maintained at 57^(@)C . (a) Find the amount of radiation falling on the ball per second. (b) Find the net rate of heat flow to or from the ball at an instant when its temperature is 200^(@)C . Stefan constant =6.0xx10^(-s)Wm^(-2)K^(-4) .

RESONANCE ENGLISH-HEAT TRANSFER-Advancel Level Problems
  1. Seven rods A, B, C, D, E, F and G are joined as shown in figure. All t...

    Text Solution

    |

  2. Find the rate of heat flow through a cross section of the rod shown in...

    Text Solution

    |

  3. A solid aluminium sphere and a solid copper sphere of twice the radius...

    Text Solution

    |

  4. A hot body placed in a surrounding of temperature theta(0) obeys Newto...

    Text Solution

    |

  5. Find the total time elapsed for a hollow copper sphere of inner radius...

    Text Solution

    |

  6. A metal block of heat capacity 90J//.^(@)C placed in a room at 25^(@)C...

    Text Solution

    |

  7. A hollow tube has a length l, inner radius R(1) and outer radius R(2) ...

    Text Solution

    |

  8. Calculate thermal conductance for radial flow of an annular cylinder o...

    Text Solution

    |

  9. Calculated thermal conductance for radial flow of a spherical sheel of...

    Text Solution

    |

  10. A metallic cylindrical vessel whose inner and outer radii are r1 and r...

    Text Solution

    |

  11. A uniform cylinder of length L and thermal conductivity k is placed on...

    Text Solution

    |

  12. Assume that the total surface area of a human body is 1.6m^(2) and tha...

    Text Solution

    |

  13. The surface of a household radiator has an emissivity of 0.55 and an a...

    Text Solution

    |

  14. A man, the surface area of whose skin is 2m^(2) , is sitting in a room...

    Text Solution

    |

  15. An electric heater is used in a room of total wall area 137m^(2) to ma...

    Text Solution

    |

  16. A rod of length l with thermally insulated lateral surface consists of...

    Text Solution

    |

  17. Two block with heat capacities C(1) and C(2) are connected by a rod...

    Text Solution

    |