Horatio drew a diagram to illustrate how magnetism is produced by electric currents. A copper colored wire has arrows emerging from its sides pointing away. The arrows are labeled magnetic field. Which best explains Horatio’s error? Magnetism is not produced by electric currents unless the wire is coiled. The magnetic field does not continually spread outward from the wire. The magnetic field is produced inside the wire, not outside of it. Magnetism is only produced when a metal bar is placed near the wire.