AN INTERACTIVE MOBILE LEARNING TOOL FOR LARGE CLASS-ROOM TEACHING AND ASSESSMENT

A method is provided for forming a molten oxide ceramic electrode for a plasma arc ignited between first and second electrodes within a plasma arc chamber, wherein the conductivity the oxide ceramic is a function of temperature alone. Following ignition of the plasma arc, a mixture is formed of a small quantity of molten oxide ceramic and a sufficiently high concentration of a volatile contaminant to render the mixture electrically conductive. The plasma arc is then transferred from one of the electrodes to the mixture. The temperature of the mixture is raised sufficiently to render the oxide ceramic electrically conductive. Finally, the volatile contaminant is progressively removed from the mixture so as to leave an electrode composed of substantially pure molten oxide ceramic.