Figure 7. When the primary coil and the secondary coil are far apart, the primary coil becomes a transmitting antenna and the secondary coil becomes a receiving antenna. There is the mutual energy flow from the primary coil to the secondary coil

From

Energy Conservation Law and Energy Flow Theorem for Transformer, Antenna and Photon

Shuang-ren Zhao

International Journal of Physics. 2023, 11(2), 56-66 doi:10.12691/ijp-11-2-1