Which of the following principle is used to produce

Solution

Magnetic refrigeration is a cooling technology based on the magneto- caloiic effect. This technique can be used to attain extremely low temperatures, as well as the ranges used in common refrigerators, depending on the design of the system. The magneto- caloric effect (MCE, from magnet and calorie) is a magneto-thermodynamic phenomenon in which a change in temperature of a suitable material is caused by exposing the material to a changing magnetic field.