A refrigerator works on the principle of:

The correct answer is Thermodynamics. A refrigerator operates based on the principles of thermodynamics, specifically the second law, which dictates the direction of heat flow. Refrigerators use a refrigeration cycle to transfer heat from a colder space (inside the fridge) to a warmer space (the room), which requires work input, typically from a compressor. This process is a direct application of thermodynamic principles. Conservation of Mass, Electromagnetism, and Newton's Laws are fundamental physics concepts but do not directly describe the primary mechanism of heat transfer and cooling in a refrigerator.