Faraday models a wire placed in a magnetic field.  Both the position of the wire and strength of the magnetic field may be time dependent although it is usually not a good idea have both types of changes occurring simultaneously.)   The default configuration consists of a U shaped wire with a slider although JavaScript can be used to create other wires, such as circular loops and rectangles.  Setting the dragable property of the active wire to true will disable the position function, x(t), and allow the user to experiment observe the relationship between the slider velocity, field strength and voltage.