Hello, I am wondering if anyone can help me with the following question. I want to find out how the size of the core in an inductor influences the current induced in the secondary coil, and whether a smaller core is more efficient if efficiency is defined as inducing the highest current in the secondary coil relative to the power required by the primary coil. Let’s say there are two O core inductors, operating at the same frequency. The core in Inductor A is twice the size as Inductor B. The primary coil in Inductor A has twice the number of turns as B, for example Inductor A’s primary coil is 100 mm long and has 100 turns, while Inductor B’s primary coil is 50mm long with 50 turns. They both have the same turn density, and the FEMM simulations I have done show each Inductor producing the same Magnetic Field strength. Does this mean that the current induced in the secondary coil would be the same in both inductors? Both Inductors receive the same level of current in the primary coil, however there is less resistance in Inductor B’s coil because the wire is half the length. Does this mean that Inductor A will need more power in the primary coil to produce the same magnetic filed strength and induce the same level of current in the secondary coil? I know that the inductance is greater in Inductor A, but I am not sure how that fits into the equation. If someone could point out the errors in my thinking, it would be appreciated. Thanks!