Home
Class 11
PHYSICS
Earth gains energy from the sun at a rat...

Earth gains energy from the sun at a rate of `8.4 J cdot cm^(-2) cdot "min"^(-1)`. A black coloured calorimeter, having water equivalent of 15g, contains 100 g water at `25^(@)C`. The calorimeter is kept at the focus of a convex lens facing the sun. If the aperture of the lens is `1000 cm^(2)`, how much time will the water take to reach its boiling point?

Text Solution

Verified by Experts

The correct Answer is:
4.3 min
Promotional Banner

Topper's Solved these Questions

  • FIRST AND SECOND LAW OF THERMODYNAMICS

    CHHAYA PUBLICATION|Exercise Exercise - Hots Numerical Problems (Marks 3/4/5)|28 Videos

  • FIRST AND SECOND LAW OF THERMODYNAMICS

    CHHAYA PUBLICATION|Exercise Entrance Corner - Assertion-reason type|4 Videos

  • FIRST AND SECOND LAW OF THERMODYNAMICS

    CHHAYA PUBLICATION|Exercise Exercise - Problem Set - I (Marks 2)|18 Videos

  • EXPANSION OF SOLIDS AND LIQUIDS

    CHHAYA PUBLICATION|Exercise CBSE SCANNER|2 Videos

  • FRICTION

    CHHAYA PUBLICATION|Exercise CBSE SCANNER|7 Videos

Similar Questions

Explore conceptually related problems

600 g of water at 30^(@)C is kept in a vessel of water equivalent 60 g. If the vessel is supplied heat at the rate of "100 cal.s"^(-1) , how much time will the water take to reach its boiling point?

When 210 g of water at 80^(@)C is kept in a calorimeter of water equivalent 90 g, its temperatue decreases to 60^(@)C in 10 min. If the water is replaced by a liquid of mass 100 g, the same fall in temperature takes place in 5 min. If the rate of cooling is the same in both cases, what is the specific heat capacity of the liquid ?

A calorimeter of water equivalent 10 g contains 100 g of water at 90^(@)C . On exposure to air, its temperature falls to 80^(@)C in 5 min. If the same calorimeter is filled with 50 g of an oil, the time for the same drop in temperature is 2 min. Calculate the specific heat of the oil if the rate of heat loss in both the cases is assumed to be the same.

A liquid kept in a calorimeter cools down from 50^(@)C to 40^(@)C in 2 minutes, and an equal volume of water in that calorimeter takes 5 minutes to cool down through the same range of temperature. If the mass of the water is 100 g and that of the liquid is 85 g. then calculate the specific heat of the liquid. Water equivalent of the calorimeter = 10 g.

Find out the amount of work done to convert 100 g ice at 0^(@)C to water at 100^(@)C . (Latent heat of fusion of ice = 80 cal cdot g^(-1) , mechanical equivalent of heat = 4.2 J cdot cal^(-1)) .

Sea water is splattered horizontally from a jet at a speed of 10 m cdot s^(-1) . The water comes to rest after falling in a container, 20 m below the jet level. What will be the increase in the temperature of the water? Specific heat of sea water = 0.94 cal cdot g^(-1) cdot^(@)C^(-1), J = 4.2 xx 10^(7) erg cdot cal^(-1) .

The top of a waterfall is at a temperature 0.49^(@)C below that of the bottom. The work done by water due to its fall is converted entirely into heat. Find the height of the waterfall. Given, g = 980 cm cdot s^(-2), J = 4.2 J cdot cal^(-1) .

A geyser heats water flowing at the rate of 3.0 litres per minute from 27^(@)C to 77^(@)C . If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combination is 4.0 xx 10^(4) J cdot g^(-1) ?

Water of volume 2 L in a container is heated with a coil of 1 kW at 27^(@)C . The lid of the container is open and energy dissipates at rate of "160 J . S"^(-1) . In how much time (in minutes) temperature will rise from 27^(@)C to 75^(@)C ? ["Given specific heat of water is 4.2 kJ . kg"^(-1)]

CHHAYA PUBLICATION-FIRST AND SECOND LAW OF THERMODYNAMICS-Exercise - Problem Set - II (Marks 3 or 4)
  1. What will be the difference in temperature between the top and the bot...

    Text Solution

    |

  2. A lead bullet hits a target at a velocity of 300 m cdot s^(-1). If it ...

    Text Solution

    |

  3. Earth gains energy from the sun at a rate of 8.4 J cdot cm^(-2) cdot "...

    Text Solution

    |

  4. The mean velocity of raindrops is 20 m cdot s^(-1) . When these drops ...

    Text Solution

    |

  5. A hole is made in a piece of iron of mass 200 g with the help of a 186...

    Text Solution

    |

  6. The speed of a 50 kg heavenly object reduces from 30 km cdot "min"^(-1...

    Text Solution

    |

  7. Sea water is splattered horizontally from a jet at a speed of 10 m cdo...

    Text Solution

    |

  8. Find out the minimum height from which a piece of ice at 0^(@)C should...

    Text Solution

    |

  9. A lead bullet melts on hitting a fixed target. What will be the minimu...

    Text Solution

    |

  10. A certain volume of a gas expands at one standard atmosphere pressure ...

    Text Solution

    |

  11. The volume of 1 mol of a gas is doubled when it expands isothermally a...

    Text Solution

    |

  12. 70 cal of heat is required to increase the temperature of 2 mol of an ...

    Text Solution

    |

  13. What will be the change in internal energy of 128 g of oxygen gas at c...

    Text Solution

    |

  14. What will be the increase in temperature if dry air at 27^(@)C is comp...

    Text Solution

    |

  15. The tyre of a motorcar bursts suddenly when air was being pumped in it...

    Text Solution

    |

  16. Calculate the amount of work done, if 20 g of hydrogen gas is compress...

    Text Solution

    |

  17. Some amount of gas at 27^(@)C is suddenly compressed to 27 times its ...

    Text Solution

    |

  18. In an adiabatic process where pressure is increased by 2/3%, if (Cp)/(...

    Text Solution

    |

  19. The volume of air increases by 2% in its adiabatic expansion. Calculat...

    Text Solution

    |

  20. Air at 27^(@)C and 128 atm pressure is filled in a container in resear...

    Text Solution

    |