Choking coils for use in electrical equipment; magnetic cores for choking coils; electric reactors; magnetic cores for electric reactors; current sensors; magnetic cores for current sensors; magnetic cores for electromagnetic solenoid valves; power transformer for amplification; magnetic cores for power transformer; electronic inductors; electric transformers; capacitors; electric resistances; choking coils for use in electrical apparatus; impedance choking coils for use in electrical apparat...