Why are the iron cores of most induction coils laminated?

The principle behind laminating the iron cores of induction coils is primarily focused on reducing the effects of eddy currents. When a magnetic field fluctuates in a conductor, it can induce circulating currents known as eddy currents. These eddy currents can result in energy losses in the form of heat, reducing the efficiency of the coil.

By laminating the iron core—constructing it from multiple thin layers of magnetic material insulated from one another—the path for these eddy currents is restricted. This design drastically decreases their magnitude, as it increases the resistance to the flow of these currents. Consequently, laminating enhances the overall performance and efficiency of induction coils, allowing for better magnetic performance despite fluctuating magnetic fields without significant energy loss. Thus, laminating is an essential technique in improving the operational efficacy of induction coils.