The ring launcher consists of a vertically mounted solenoid of thick copper wire
with an iron core. The coil is energized with by pressing the push button on the
panel. Two aluminium rings are supplied with the apparatus. These rings fit over
the solenoid and are supported at some height above the base by an adjustable
collar. The behaviour of the rings when the coil is energized depends on the type
of the ring placed over the coil at the time. The solid aluminium ring is propelled
straight up while the slotted ring remains static, thus demonstrating the principle
of electromagnetic induction as well as Lenz law.
