Marconi's Law
Ideal Transformer equation - Voltages
Ideal Transformer equation - Currents
Helmholtz free energy
Helmholtz coil ( the magnetic field at the center point)
Heat flow in electronics - maximum power dissipate
Free-Space Path Loss (in dB)
Faraday - Lenz law (for a tightly wound coil of wire)
Electrical resistivity (general definition)
Electrical resistance