In an electromagnetic wave diagram, the x-axis typically represents space or time, while the y-axis represents the amplitude or intensity of the wave.
If the x-axis represents space, then different points along the x-axis correspond to different positions in space. The y-axis indicates the amplitude or intensity of the electromagnetic wave at each point in space. By observing the variation in the y-axis as you move along the x-axis, you can determine how the intensity or amplitude of the wave changes with respect to position.
If the x-axis represents time, then different points along the x-axis correspond to different moments in time. The y-axis indicates the amplitude or intensity of the electromagnetic wave at each point in time. By examining the y-axis as time progresses, you can observe how the intensity or amplitude of the wave evolves over time.
In both cases, the y-axis provides information about the strength or magnitude of the electromagnetic wave at different spatial or temporal locations. It allows us to understand how the wave's intensity changes as we move through space or progress in time. The pattern of the wave's variation along the x-axis gives insights into its spatial distribution or temporal evolution.