Home
Class 11
PHYSICS
A sphere of density 'd' specific heat ca...

A sphere of density 'd' specific heat capacity 'c' and radius 'r' is hung by athermally insulating thread in an enclosure which is kept at lower temperature than the shpere The temperature of the sphere starts to drop at rate which is proportional to .

A

`c//r^(3)d`

B

`1r^(3)dc`

C

`3r^(3)dc`

D

`1//rdc`

Text Solution

Verified by Experts

The correct Answer is:
D
`ms(d theta)/(dt)=KA(theta-theta_(0))`
`((4)/(3)pir^(3))d xxc(d theta)/(dt)=K4pir^(2)(theta-theta_(0))`
`(d theta)/(dt)prop(1)/(rdc)` .
Promotional Banner

Topper's Solved these Questions

  • TRANSMISSION OF HEAT

    NARAYNA|Exercise NCERT BASED QUESTIONS|5 Videos

  • TRANSMISSION OF HEAT

    NARAYNA|Exercise SINGLE ANSWER QUESTIONS Passage|1 Videos

  • TRANSMISSION OF HEAT

    NARAYNA|Exercise LEVEL-III (C.W)|1 Videos

  • THERMODYNAMICS

    NARAYNA|Exercise Exercise|187 Videos

  • UNITS AND MEASUREMENTS

    NARAYNA|Exercise STATEMENT TYPE QUESTION|23 Videos

Similar Questions

Explore conceptually related problems

A sphere of density d , specific heat s and radius r is hung by a thermally insulating thread in an enclosure which is kept at a lower temperature than the sphere. The temperature of the sphere starts to drop at a rate which depends upon the temperature difference between the sphere and the enclosure. If the temperature difference is DeltaT and surrounding temperature is T_(0) then rate of fall in temperature will be [Given that DeltaT lt lt T_(0) ]

A solid copper sphere of density rho , specific heat c and radius r is at temperature T_1 . It is suspended inside a chamber whose walls are at temperature 0K . What is the time required for the temperature of sphere to drop to T_2 ? Take the emmissivity of the sphere to be equal to e.

A solid copper shere of density rho specific heat c and radius r is at temperature T_(1) It is suspended inside a chamber whose walls are at temperature 0 K The time required for the temperature of sphere to drop to T_(2) is (rrhoc)/(xesigma)((1)/(T_(2)^(3))-(1)/(T_(1)^(3))) Find the value of x? Take the emmissivity of teh sphere to be equal to e .

A sphere of radius r, density, rho and specific heat s is heated to temperature theta and then cooled in an enclosure at temperature theta_(0) . How , the rate of fall of temperature is related with r, rho and s?

A solid copper sphere (density rho and specific heat c) of radius r at an initial temperature 200K is suspended inside a chamber whose walls are at almost 0K. The time required for the temperature of the sphere to drop to 100K is …….

A solid sphere of radius 'R' density 'rho' , and specific heat 'S' initially at temperature T_0 Kelvin is suspended in a surrounding at temperature 0 K. Then the time required to decrease the temperature of the sphere from T_0 to T_0/2 Kelvin is alpha xx (rhoSR)/(sigmaT_0^3) . Find alpha . (Assume sphere behaves like a black body )

A solid sphere of radius 'R' density rho and specific heat 'S' initially at temperature T_(0) Kelvin is suspended in a surrounding at temperature 0K. Then the time required to decrease the temperature of the sphere from T_(0) to (T_(0))/(2) kelvin is (Assume sphere behaves like a black body)

Radius of a shere is R density is d and specific heat is s, Is is heated and then allowed to cool Its rate of decrease of temperature will be proportional to .

NARAYNA-TRANSMISSION OF HEAT-LEVEL- (C.W)
  1. A and B are two points on uniform metal ring whose centre is O The ang...

    Text Solution

    |

  2. Two ends of a conducting rod of varying cross-section are maintained a...

    Text Solution

    |

  3. Three rods of same dimensions are arranged as shown in Fig. They have ...

    Text Solution

    |

  4. A boiler is made of a copper plate 2.4mm thick with an inside coating ...

    Text Solution

    |

  5. Ice starts forming in lake with water at 0^(@)C and when the atmospher...

    Text Solution

    |

  6. A long metallic bar is carrying heat from one of its ends to the other...

    Text Solution

    |

  7. The temperature drop through each layer of a two layer furnace wall is...

    Text Solution

    |

  8. The wall with a cavity consists of two layers of brick separated by a ...

    Text Solution

    |

  9. A ring consisting of two parts ADB and ACB of same conductivity k carr...

    Text Solution

    |

  10. Two metallic spheres S1 and S2 are made of the same material and have ...

    Text Solution

    |

  11. The temperature of an spherical isolated black body falls from T(1) an...

    Text Solution

    |

  12. A star behaves like a perfectly black body emitting radiant energy The...

    Text Solution

    |

  13. A sphere of density 'd' specific heat capacity 'c' and radius 'r' is h...

    Text Solution

    |

  14. Assuming the Sun to be a spherical body of radius R at a temperature o...

    Text Solution

    |

  15. The spectral emissive power E(lambda) for a body at temperature T(1) i...

    Text Solution

    |

  16. A heated object (at time t=0 and temperature T=T(0)) is taken out of t...

    Text Solution

    |

  17. A system S receives heat continuously from an electric heater of power...

    Text Solution

    |

  18. According to Newton's law of cooling, the rate of cooling of a body is...

    Text Solution

    |

  19. A liquid in a beaker has temperature theta(t) at time t and theta0 is ...

    Text Solution

    |

  20. If a piece of metal is heated to temperature theta and the allowed to ...

    Text Solution

    |