Useful for exploring the principle of working of capacitance, and the relationship between charge, voltage and capacitance. Comprises a pair of adjustable circular metal discs of diameter 100mm attached to the insulated handles and is supported on insulated pillars mounted vertically on a base. Another pillar has a clamp for holding glass dielectric plate between the metal discs. The glass plate may be replaced by plates of other material to study the effect of dielectric. End of insulating handles of metals discs carry a 4mm socket for electrical connection.