Question

The refrigerator cools your food and drink. The cooling is due to:

• A. expansion of ice
• B. the expansion of the refrigerant gas
• C. the work of the electric motor
• D. reaction of the refrigerant gas

Answer 1

Answer: (B)

the expansion of the refrigerant gas

The working principle of a refrigerator is very simple, it involves the removal of heat from one region and its deposition to another. When you pass a low-temperature liquid close to object that you want to cool, heat from those objects is transferred to the liquid, which evaporates and takes away the heat in the process.

You may already know that gases heat up when you compress them and cool down when they are allowed to expand. That's why a bicycle pump feels warm you use it to pump air inside a tire, while sprayed perfume feels cool.