A very low inductance, very low resistance, command operated repetitive high current opening switch is described which uses a Lorentz force to move a conductive liquid between a conducting region and an insulated region between two electrodes. In a specific embodiment, a cylindrical outer electrode coaxially surrounds in a spaced relationship a generally cylindrical inner electrode. The annular space between the inner and outer electrodes is divided into first and second sections along the length of the electrodes. Intermeshing continuous spiral fins are defined on the facing surfaces of the inner and outer electrodes along the first section of the length of the opening switch. Insulation covers the surfaces of the inner and outer electrodes surrounding the second section. An electrically conductive liquid is sealed inside the first and second annular sections in an amount sufficient to substantially fill only one of the annular sections, so that electric current can flow between the outer electrode and the inner electrode through the liquid whenever any of the liquid is inside the first annular section, but the insulation prevents the flow of electric current flow between the outer electrode and the inner electrode when all of the liquid is inside the second annular section. A pulsed magnetic field created by a coil surrounding the first annular section outside the outer electrode produces a tangental Lorentz force which corkscrews the conductive fluid from one annular section to another.