alloy alternating current bobbin capacitance capacitor coil differential equation direct current eddy current electric current electrical conductor electrical resistance electrical steel electricity electromagnetic coil electromotive force electronic component electronic filter electronics energy exponential decay fault current flywheel gyrator henry high frequency hum hydraulic analogy hysteresis inductance induction coil induction cooker induction loop integrated circuit joule laminate laplace transform linear circuit liquid helium liquid nitrogen magnetic core magnetic field magnetic flux memristor parasitic capacitance printed circuit board public utility q factor rlc circuit rl circuit reactor resistivity resistor resonance saturable reactor series and parallel circuits spiral square metre superconducting magnetic energy storage switched-mode power supply torus transformer transistor turbine vacuum