Home
Class 12
PHYSICS
The temperature of a room heated by heat...

The temperature of a room heated by heater is `20^@C` when outside temperature is `-20^@C` and it is `10^@C` when the outside temperature is `-40^@C`. The temperature of the heater is

A

`80^(@)C`

B

`100^(@)C`

C

`40^(@)C`

D

`60^(@)C`

Text Solution

Verified by Experts

The correct Answer is:
D
Heat released to room = Heat dissipated out room.
Let temperature of heater is T
`T-20=20-(-20)`
`implies T-20=40`
`T=60^(@)C`
Also, `T-10=10-(-40)`
`implies T-10=50`
`implies T=60^(@)C`
Promotional Banner

Topper's Solved these Questions

  • HEAT TRANSFER

    PHYSICS GALAXY - ASHISH ARORA|Exercise Advance MCQs with One or More Option Correct|20 Videos

  • HEAT TRANSFER

    PHYSICS GALAXY - ASHISH ARORA|Exercise Unsolved Numerical Problems for Preparation of NSEP,INPhO&IPhO|66 Videos

  • HEAT TRANSFER

    PHYSICS GALAXY - ASHISH ARORA|Exercise Conceptual MCQs Single Option Correct|24 Videos

  • HEAT AND THERMAL EXPANSION

    PHYSICS GALAXY - ASHISH ARORA|Exercise UNSOLVED NUMRICAL PROBLEMS FOR PREPARATION OF NSEP, INPhO & IPhO|82 Videos

  • Kinetic Theory of Gases and Gas Laws

    PHYSICS GALAXY - ASHISH ARORA|Exercise Unsolved Numerical Problems for Preparation of NSEP, INPhO & IPhO|64 Videos

Similar Questions

Explore conceptually related problems

A radiator whose temperature is T^(@)C is used to heat the room in the cold weater The radiator is able maintain a room temmperature of 30^(@)C when ouside temperature is 10^(@)C and 15^(@)C when outside temperature is 30^(@)C Determine the temperature of the radiator [Assume Newton's law of cooling to be valid] .

A hot body is kept in cooler surroundings. Its rate of cooling is 3^(@)C /min when its temperature is 60^(@)C and 1.5^(@)C / min when its temperature is 45^(@)C . Determine the temperature of the surroundings and the rate of cooling when the temperature of the body is 40^(@)C

Critical temperature of CO _(2) is 31.2 ^(@)C. In summer, the room temperature is 40^(@)C, then

The amount of heat conducted out per second through a window, when inside temperature is 10^(@)C and outside temperature is -10^(@)C , is 1000 J. Same heat will be conducted in through the window, when outside temperature is -23^(@)C and inside temperature is:

A room is heated by a radiator that has a constant temperature T (unknown). When the outside temperature is 260 K, the room temperature is 300 K. However, when the outside temperature drops to 240 K, the room temperature is only 290 K. Estimate the radiator temperature T.

If the temperature of City A is -20 ""^(@)C and the temperature of City B is 10 ""^(@)C , the difference in temperature between the two cities is

In a copper-iron thermocouple , the temperature of cold junction is 20^(@) C and the neutral temperature is 280^(@)C . Find the temperature of inversion.

An electric heater is used in a room of total wall area 137m^(2) to maintain a temperature of +20^(@)C inside it when the outside temperature is -10^(@)C . The walls have three different layers materials . The innermost layer is of wood of thickness 2.5 cm, in the middle layer is od cement of thickness 1.0 cm and the outermost layer is of brick of thickness 25.0 cm. find the power of the electric heater. Assume that there is no heat loss through the floor and the ceiling. The thermal conductives of wood, cement and brick are 0.125, 1.5 and 1.0 watt//m// .^(@)C respectively.

An electric heater is placed inside a room of total wall area 137 m^2 to maintain the temperature inside at 20^@C . The outside temperature is -10^@C . The walls are made of three composite materials. The inner most layer is made of wood of thickness 2.5 cm the middle layer is of cement of thickness 1 cm and the exterior layer is of brick of thickness 2.5 cm. Find the power of electric heater assuming that there is no heat losses through the floor and ceiling. The thermal conductivities of wood, cement and brick are 0.125 W//m^@-C, 1.5W//m^@-C and 1.0 W//m^@-C respectively.

PHYSICS GALAXY - ASHISH ARORA-HEAT TRANSFER -Numerical MCQs Single Options Correct
  1. You are given two spheres of same material and radii 10 cm and 20 cm. ...

    Text Solution

    |

  2. An object is cooled from 75^(@)C to 65^(@)C in 2 min in a room at 30^(...

    Text Solution

    |

  3. The temperature of a room heated by heater is 20^@C when outside tempe...

    Text Solution

    |

  4. The thermal conductivity of two materials are in the ratio 1 : 2. What...

    Text Solution

    |

  5. Two rods made of same material having same length and diameter are joi...

    Text Solution

    |

  6. The maximum radiations from two bodies correspond to 560 nm and 420 nm...

    Text Solution

    |

  7. A ball is coated with lamp black. Its temperature is 327^(@)C and is p...

    Text Solution

    |

  8. Two metallic rods are connected in series. Both are of same material o...

    Text Solution

    |

  9. A compound slab is made of two parallel plates of copper and brass of ...

    Text Solution

    |

  10. Consider the two insulating sheets with thermal resistance R(1) and R(...

    Text Solution

    |

  11. Two cylindrical rods of same meterial have the same temperature differ...

    Text Solution

    |

  12. An object is at temperature of 400^(@)C. At what approximate temperatu...

    Text Solution

    |

  13. A wall has two layers A and B, each made of different material. Both t...

    Text Solution

    |

  14. The ratio of the coefficient of thermal conductivity of two different ...

    Text Solution

    |

  15. A cylindrical rod with one end in a steam chamber and the other end in...

    Text Solution

    |

  16. There is ice formation on a tank of water of thickness 10 cm.How much ...

    Text Solution

    |

  17. The rectangular surface of area 8 cm xx 4 cm of a black body at temper...

    Text Solution

    |

  18. The emissivity and surface area of tungsten filament of an electric bu...

    Text Solution

    |

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

    Text Solution

    |

  20. Which of the following cylindrical rods of the same metal has the high...

    Text Solution

    |