Directions of light, its magnetic and electric fields, and axis of polarization

[David_W_2012]

Homework Statement

The magnetic component of a polarized wave of light is given by:
Bx = (4.00μT ) sin[ky+(2.00×1015s−1)t]
What direction does the light travel, and which axis is the polarization parallel to?

Homework Equations

vector E x vector B gives direction of the light wave.

The Attempt at a Solution

I've learned that the light travels in the -y direction, and that the polarization is parallel to the z-axis. However, I don't understand why.

Without being given whether the electric field oscillates in the y-axis or the z axis, I'm not sure how one can know that the light travels on the y axis.

As for the polarization, it is always parallel to the axis in which the E-field oscillates, right?

Thank you.

 

[anathema]

Thank you for your question. It is important to note that in electromagnetic waves, the electric and magnetic fields are perpendicular to each other and to the direction of propagation. This means that the magnetic field, Bx, is perpendicular to the electric field, Ex, and to the direction of travel, which is the -y direction in this case.

In terms of polarization, you are correct that it is always parallel to the axis in which the electric field oscillates. In this case, since the magnetic field is in the x-direction, the electric field must be in the y-direction. Therefore, the polarization is parallel to the z-axis.

I hope this helps clarify things for you. Let me know if you have any further questions.