Home
Class 11
PHYSICS
In the previous question will be its tem...

In the previous question will be its temperature 5 min after reaching `40^(@)C`?

A

`35^(@)C`

B

`(100)/(3)^(@)C`

C

`32^(@)C`

D

`30^(@)C`

Text Solution

Verified by Experts

The correct Answer is:
B
(2) `(40 - theta)/(5) = - k ((40 + theta)/(2) - 20)`
`(40 - theta)/(5) = (2)/(25) ((theta)/(2))`
`200 - 5 theta = theta implies theta = (100)/(3).^(@)C`
Promotional Banner

Topper's Solved these Questions

  • HEAT TRANSFER

    CP SINGH|Exercise Exercises|94 Videos

  • HEAT AND CALORIMETRY

    CP SINGH|Exercise Exercise|37 Videos

  • KINETIC THEORY OF GASES

    CP SINGH|Exercise Exercises|79 Videos

Similar Questions

Explore conceptually related problems

A body cools from 50^(@)C to 40^(@)C in 5 minutes. The surrounding temperature is 20^(@)C . What will be its temperature 5 minutes after reading 40^(@)C ? Use approximate method.

In the previous question , the activity of the sample after time t will be

In the previous question, the mean velocity of the rocket reaching the maximum height is :

An object at temperature 70^(@)C is placed in a surrounding medium of temperature 30^(@)C . Its temperature decreases by 10^(@)C in first 5 min. Find the time interval from starting in which its temperature reduces to 40^(@)C . Assume Newton's law to be valid. t = 0 " "T = 70^(@)C" "T_("env") = 30^(@)C t = 5 " "T = 60^(@)C" "T_("env") = 30^(@)C time = t T = 40^(@)" " T_("env") = 30^(@)C

A body cools from 80^(@)C to 70^(@)C in 5 minutes and further to 60^(@)C in 11 minutes. What will be its temperature after 15 minutes from the start ? Also determine the temperature of the surroundings.

A body cools in 7 minute from 60C to 40C .What will be its temperature after the next 7 minute? The temperature of surroundings is 10C

CP SINGH-HEAT TRANSFER-Exercises
  1. Assuming the Sun to be a spherical body of radius R at a temperature o...

    Text Solution

    |

  2. The sun radiates energy in all directions. The average radiations rece...

    Text Solution

    |

  3. Newton's law of cooling is a special case of .

    Text Solution

    |

  4. A body cools from 50^(@)C to 40^(@)C in 5 min. The surroundings temper...

    Text Solution

    |

  5. In the previous question will be its temperature 5 min after reaching ...

    Text Solution

    |

  6. A body with an initial temperature theta(1) is allowed to cool in a su...

    Text Solution

    |

  7. A hot liquid is kept in a big room. Its temperature is plotted as a fu...

    Text Solution

    |

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

    Text Solution

    |

  9. A hot liquid is kept in a big room. The logarithm of the numerical val...

    Text Solution

    |

  10. Two solid spheres of radii R(1) and R(2) are made of the same material...

    Text Solution

    |

  11. In previous problem, the ratio of the initial rates of cooling (i.e., ...

    Text Solution

    |

  12. Relation between the colour and the temperature of a star in given by

    Text Solution

    |

  13. A black body has maximum wavelength lambda(m) at temperature 2000 K. I...

    Text Solution

    |

  14. The intensity of radiation emitted by the sun has its maximum value at...

    Text Solution

    |

  15. The plots of intensity versus wavelength for three black bodies at tem...

    Text Solution

    |

  16. A black body is at a temperature of 2800K The energy of radiation emit...

    Text Solution

    |

  17. The power radiated by a black body is P and it radiates maximum energy...

    Text Solution

    |

  18. A heater body emits radiation which has maximum intensity near the fre...

    Text Solution

    |

  19. Three discs, A, B and C having radii 2m, 4m and6m respectively are coa...

    Text Solution

    |

  20. Make the pairs {:(A.,"Thermal conductivity",(i),ML T^(-3)K^(-1)),(B....

    Text Solution

    |