At a certain instant in time,the $\vec { E }$ field of an electromagnetic wave in a vacuum points in the -z direction,and the $\vec { B }$ field points in the +y direction.In what direction is this wave traveling?
A)+x direction
B)-x direction
C)+y direction
D)-z direction
E)+z direction

Question

Quizplus · Accepted Answer

The direction of wave propagation in an electromagnetic wave is given by the cross product $\vec{E} \times \vec{B}$. Given $\vec{E}$ is in the -z direction and $\vec{B}$ is in the +y direction, the cross product points in the +x direction, indicating the wave is traveling in the +x direction.

At a Certain Instant in Time,the E⃗\vec { E }E Field of an Electromagnetic Wave in a Vacuum Points in Field

At a Certain Instant in Time,the $\vec { E }$ Field of an Electromagnetic Wave in a Vacuum Points in Field