Question

An electromagnetic wave is traveling straight down toward the center of the Earth. At a certain moment in time the electric field points west. In which direction does the magnetic field point at this moment?

Answer 1

North

Step-by-step explanation:

In an electromagnetic wave, the direction of the wave, the direction of the electric field and the direction of the magnetic field are all perpendicular to each other.

Therefore, we can find the direction of the magnetic field by using the right hand rule. We have:

- Index finger: direction of motion of the wave --> toward the center of Earth

- middle finger: direction of the electric field --> west

- thumb: direction of the magnetic field --> north

So, the magnetic field points north.