Question

If the door of a refrigerator is kept open then which of the following is true?
A. Room is closed
B. Room is heated
C. Both A & B
D. None of these.

Answer 1

We know that a fridge or refrigerator can be considered as a "heat pump". It carries air inside the fridge and cools the air by removing heat. Whenever we touch the back of a fridge from outside, it is usually warm if the refrigerator unit is running.

Complete step by step answer: A refrigerator is a heat engine. It will basically extract the heat from a reservoir possessing low temperature and transfer it to high temperature. So, as given, if the door of the refrigerator is kept open, then the room will become hotter as the refrigerator releases more heat into the room than earlier. Hence, by this way, the temperature of the room increases and the room becomes hot. So, if you are thinking that a room can be cooled by keeping the door of a refrigerator open, then you are wrong.
Hence, the right answer to this question is option B.

Additional Information: The working of the refrigerator is based on the fact that heat is taken away from the working volume of the refrigerator by an evaporating substance termed as refrigerant taking the help of a compressor, evaporator, condenser and expansion valve. CFC is the common refrigerant used in refrigerators. But CFC is very harmful as it causes depletion of the ozone layer.

Note: Refrigerator helps in preservation of food. We know that fish products, meat, and precooked foods have short lives due to bacterial action, ageing and enzyme activities. When foods are kept in the refrigerator, the bacterial action on food is slowed down and thus food remains fresh for a longer time.