Visitors can throw a virtual switch to connect the circuit and observe the battery charge the capacitor. Once the capacitor is fully charged, the switch can be reversed to discharge the capacitor. How A Compact Disc Works - This tutorial explores how a laser beam is focused onto the surface of a spinning compact disc, and how variations between pits and lands on the disc surface affect how light is either scattered by the disc surface or reflected back into a detector. Magnetic Fields and Compass Orientation - Explore the effects of induced electromagnetic fields on the orientation of a compass. A virtual switch is provided to start and stop current flow from a battery through a coil of wire.
Visitors can turn the switch on and off to observe the effects on the compass needle orientation.
Cathode Rays - The first cathode ray tube was created British scientist Sir William Crookes. This tutorial demonstrates how the electrons create ionizing effects from residual gas, which results in the visibility of cathode rays. Principles Of Alternating Current - . The operation of metal detectors is based upon the principle of electromagnetic induction. Metal detectors contain one or more inductor coils, and this tutorial demonstrates how a single-coil detector operates.