This page takes the two laws behind an electromagnetic wave one at a time and shows them in three dimensions. The scene panel switches between a magnetic source, an electric source, and the two chained together into a travelling wave.
In the magnetic source scene, a magnetic field swings up and down inside the cylinder at the centre. Around it a curling electric field appears. The electric field is strongest not when the magnetic field is largest but when it crosses zero, because that is where it changes fastest.
The electric source scene is the mirror image. Source and curl swap places and nothing else about the construction or the motion changes. What does differ is which way the curl turns: the Faraday law carries a sign that opposes the change, and the Ampere and Maxwell law does not.
The curl arrows shorten on the outer ring. For the same rate of change, a larger ring has a longer way around, so the strength at any one place is thinned out. It falls off in inverse proportion to the distance.
The graph below the figure puts the two fields side by side against time. In the induction scenes one is a sine and the other is its rate of change, a cosine, so the two run a quarter period apart. When one is at a peak the other is passing exactly through zero.
Switch to the wave scene and the two curves land on top of each other. In a wave that travels by the fields creating each other, they are in phase. The shape changes on the same graph, so the difference between induction and propagation is there to see.
Raising the frequency in the display panel shrinks the wavelength in the wave scene. The speed is untouched, so more swings per second means a shorter length for each one, exactly as the relation says. In the induction scenes the same control only makes the swing faster.
Drag to turn the figure and scroll or pinch to move in and out. Which plane the curl turns in, and how the two fields sit at right angles, cannot be read from a single head-on view. The reset icon brings the view back to the framing for that scene at any time.