The average Hackaday reader likely knows, at least in the academic sense, what a magnetic field ... of what the field lines would look like on its electronic paper display. Relative field strength ...

or the magnetic field of a magnet. place the plotting compass near the magnet on a piece of paper mark the direction the compass needle points move the plotting compass to many different positions ...

How a Generator Works When an electric current flows through a wire, it generates a three-dimensional magnetic force field around the ... sprinkled on a sheet of paper placed over the magnet.