alkali alternate alternator ammeter ampere amplifer amplitude analog anode arc argon attract ballast band battery beam binary blackout branch brownout bulb buzzer cable capacitor cathode cell charge chip circuit coaxial computer condenser conductor configuration connection connector contact control copper couple crystal current current cycle density device diode direction discharge distort duration electrician electrode electrolysis electromagnetism element equipment excessive farad field filament filter flow flux force frequency fuse galvanometer gamma ray gas generator grid ground heat hertz humidistat impede impulse impurity incandescent inductor infrared installation insulation insulator integrate intensity interaction ion jack joule kilowatt lamp laser leads level light load loadstone loop luminous magnetism magnify mass melt microchip migration modulation motion motor negative network object ohm optics oscillate outlet output particle patch board path peak photoelectric physics point polarization positive potential power power cord probe property pulsate quantity radiation radio ratio ray receiver receptacle reference relay repel resistance resistor resonance rheostat rod schematic secondary semiconductor sensor signal socket solder solenoid spectral static static static storage supply supply surge switch target telecommunication telegraph telephone television terminal testing thermistor thermocouple thermostat tracer transducer transfer transistor transmit tube tweeter ultraviolet unit usage vacuum value velocity volt voltage watt waveform wavelength wire wire woofer wrapped x-ray zero