By opening the door of a refrigerator inside a closed room:


Correct option is

You ultimately warm the room slightly

If a refrigerator is working in a closed room with its door closed, the refrigerator will reject heat from its inside into the room continuously and so the temperature of the room will gradually increase. Now, if the door of the refrigerator is open the heat rejected by the refrigerator in the room will be more than the heat, taken by it from the room (by an amount equal to the work done by the compressor); so the temperature of the room in this case will also increase gradually but at a slower rate as compared to that in 1st case.




An ideal gas is taken through a cyclic thermo-dynamical process through four steps. The amounts of heat involved in these steps are:

    respectively. The corresponding works involved are:  respectively. The value of W4 is:


When an ideal diatomic gas is heated at constant pressure fraction of the heat energy supplied which increases the internal energy of the gas is:


70 calories of heat are required to raise the temperature of 2 moles of an ideal gas at constant pressure from 30oC to 35oC. The amount of heat required to raise the temperature of the same gas through same range (30oC to 35oC) at constant volume is:


A motor-car tyre has a pressure of 2 atmosphere at 27oC. It suddenly bursts. If (Cp/Cv) = 1.4 for air, find the resulting temperature:


Find the  amount of work done to increase the  temperature of one mole of ideal gas by 30oC, if it is expanding under the condition  (R = 8.31 J/mol-K):


For an adiabatic expansion of a perfect gas, the value of  is equal to:


In an adiabatic expansion of a gas, the product of pressure and volume:


One of the most efficient engines ever developed operates between 2100 K and 700 K. Its actual efficiency is 40%. What percentage of its maximum possible efficiency is this?


In an adiabatic change, the pressure P and temperature  of a diatomic gas are related by the relation   where equals:


One mole of an ideal mono-atomic gas is heated at a constant pressure of one atmosphere from 0oC to 100oC. Then the change in the internal energy is: