# Why isn't the direction of magnetic field all around the electric field( in circles) in an electromagnetic wave?

Why isn't the direction of magnetic field all around the electric field( in circles) in an electromagnetic wave? (Instead it is shown only in a single direction in the diagrams)

• There is a difference between a propagating electric field and an electric current Nov 20, 2020 at 14:10
• Both produces same magnetic fields Nov 20, 2020 at 14:18
• No they don't produce the same fields. Nov 20, 2020 at 14:22
• Steady electric currents make static magnetic fields. In EM waves the magnetic field changes over time. So no, they do not produce the same fields. Nov 20, 2020 at 14:43
• Another point: The magnetic field around a line of moving charge is circular. Now think about what is the form of the magnetic field around a sheet of moving charge? Nov 20, 2020 at 18:22

## 1 Answer

Both electric and magnetic fields have single direction, because it is a plane wave, propagating in single direction. All directions are perpendicular to each other.

From Maxwell's equations is follows that EM wave far from source, has magnetic field perpendicular to electric field, and both are perpendicular to line of sight towards the source.