Induction stoves work by using an electromagnetic field to generate heat directly in the cooking vessel. This process requires the presence of a material that can effectively interact with the magnetic field. While it is true that ferromagnetic metals are commonly used on induction stoves, it is not entirely accurate to say that only ferromagnetic metals work on these stoves.
Ferromagnetic materials, such as iron, nickel, and some types of stainless steel, have a special property called ferromagnetism. This property allows them to strongly respond to magnetic fields and exhibit magnetic behavior. When exposed to an alternating current (AC) magnetic field, the magnetic properties of ferromagnetic materials cause them to rapidly change their magnetic orientation, resulting in the generation of heat through a phenomenon known as hysteresis loss. This heat is then transferred to the cookware, which in turn heats up the food.
On the other hand, non-ferromagnetic materials, such as aluminum, copper, and glass, do not exhibit the same magnetic properties as ferromagnetic materials. They either have weak magnetic responses or are non-magnetic altogether. Consequently, these materials are not efficiently heated by the magnetic fields generated by induction stoves. They are not able to produce significant hysteresis losses and therefore do not heat up as effectively.
It's worth noting that some induction stoves are designed to work with non-ferromagnetic materials as well. These stoves utilize alternate heating methods, such as direct resistance heating, to generate heat in cookware made of non-ferromagnetic materials. However, the majority of induction stoves available in the market are optimized for ferromagnetic materials due to their better response to magnetic fields and greater heating efficiency.