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

David_W_2012

1. The problem statement, all variables and given/known data

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?

2. Relevant equations

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


3. 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.