Home
Class 11
PHYSICS
A refrigerator is used to mainatain eata...

A refrigerator is used to mainatain eatables kept inside it at `9^(@)C`. If the room temperature is `35^(@)C`, then calculate the coefficient to performance. Calculate the amount of heat rejected to the surrounding.

Text Solution

Verified by Experts

Given : `T_(2)=9+273=282K`
`T_(1)=36+273=309K`
Coefficient of performance `prop=(T_(2))/(T_(1)-T_(2))`
i.e., `alpha=(282)/(309=282)=10.44" ""but "(1)/(alpha)=(Q_(1))/(Q_(2))-1`
hence `(Q_(1))/(Q_(2))-(1+alpha)/(alpha)=(1+10.44)/(10.44)" "i.e., (Q_(1))/(Q_(2))=(11.44)/(10.44)=1.096`
i. e., heat rejected to the surroundings is `1.096Q_(2)J`
Promotional Banner

Topper's Solved these Questions

  • THERMODYNAMICS

    SUBHASH PUBLICATION|Exercise FIVE MARKS QUESTIONS WITH ANSWERS|6 Videos
  • THERMAL PROPERTIES OF MATTER

    SUBHASH PUBLICATION|Exercise FOUR MARKS QUESTIONS AND ANSWERS|22 Videos
  • UNITS AND MEASUREMENTS

    SUBHASH PUBLICATION|Exercise NUMERICALS WITH SOLUTIONS|13 Videos

Similar Questions

Explore conceptually related problems

A refrigerator is to maintain eatables kept inside at 9^(@)C . If room temperature is 36^(@)C , calculate the coefficient of performance.

The efficiency of a Carbot's heat engine is 0.25 . If on reducing the temperature of the sink by 50^(@)C , the efficiency increase, 0.35 , then calculate the temperature of the source and sink.

A block of wood of mass 0.5 kg is suspended by means of a thin wire. A bullet of mass 0.020 kg is fired horizontally in the plane of the block with a velocity of 100ms^(-1) . If the bullet gets stuck inside the block, then calculate the height by which the system rises (g=9.8ms^(-2)) . Calculate the amount of heat produced in the block.

The ratio of specific heats of a gas in 1.40 . There are 200 moles of gas initially present. The gas undergoes adiabatic expansion and as a result which, the temperature of the gas falls from 400 K to 100 K. Give R=8.312J "mole"^(-1) K^(-1) . Calculate the amount or work done by the gas on the surroundings.

A heating element using nichrome connected to a 230V supply draws an initial current of 3.2A which settles after a few seconds to a steady value of 2.8A. What is the steady temperature of the heating -element, if the room temperature is 27.0^(@) C? Temperature cofficient of resistance of nichrome averaged over the temperature range involved is 1.70xx 10^(-4@)C^(-1).

A cubical ice box of thermocol has each side 30 cm and thickness 5 cm , 4 kg of ice is put in the box , if outside temperature is 45^(@)C and coefficient of thermal conductivity is 0.01 J s^(-1) m^(-1) K^(-1) . Calculate the mass of ice left after 6 hrs . Take latent heat of fusion of ice as 335 xx 10^(3) JK^(-1)

At constant pressure certain quantity of water at 24^(@)C is heated. It was observed that the rise of temperature was found to be 4^(@)C per minute. Calculate the time required to rise the temperature of water to 100^(@)C at sea level by using formula.

SUBHASH PUBLICATION-THERMODYNAMICS-NUMERICALS WITH SOLUTIONS
  1. A refrigerator is used to mainatain eatables kept inside it at 9^(@)C....

    Text Solution

    |

  2. The triple points of Ne and CO(2) are 24.57K and 216.55K respectively....

    Text Solution

    |

  3. A constant volume gas theremometer using helium, records a pressure of...

    Text Solution

    |

  4. The electrical resistance in ohms of a cerbain thermomter varies with ...

    Text Solution

    |

  5. A steel tape 1 m long is correctly cailbrated for temperature of 27.0^...

    Text Solution

    |

  6. A hole is drilled in a copper sheet. The diameter of the hole is 4.24c...

    Text Solution

    |

  7. A brass wire 1.8 m long at 27^(@)C is held taut with a little tension ...

    Text Solution

    |

  8. A 10 kW drilling machine is used to drill a bore in a small aluminium ...

    Text Solution

    |

  9. A copper block of mass 2.5 kg is heated in a furance to temperature of...

    Text Solution

    |

  10. A geyser heats water flowing at the rate of 3.0 litres per minute from...

    Text Solution

    |

  11. What amount of heat must be supplied to 2.0xx10^(-2)kg of N(2) (at roo...

    Text Solution

    |

  12. A tyre pumped at a pressure of 3.375 atm and at 27^(@)C suddenly burst...

    Text Solution

    |

  13. The volume of 1 kg water is reduced by 91cm^(3) on melting. Calculate ...

    Text Solution

    |

  14. A gas expands from 75 litre to 125 litre at a constant pressure of 4 a...

    Text Solution

    |

  15. Calculate the amount of work done in taking the gas from the state (i)...

    Text Solution

    |

  16. 1g of water at atmospheric pressure and at 100^(@)C, 1671 cm^(3) of w...

    Text Solution

    |

  17. The efficiency of a Carbot's heat engine is 0.25. If on reducing the t...

    Text Solution

    |

  18. The volume of N(2) gas increases from 1 cm^(3) "to" 100 cm^(3) at ...

    Text Solution

    |

  19. The ratio of specific heats of a gas in 1.40. There are 200 moles of g...

    Text Solution

    |

  20. The working substance in a Carnot's heat engine absorbs 5xx10^(6)J of...

    Text Solution

    |