## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

To find the direction of the electromagnetic wave, we can find $E \times B$ To apply the right hand rule to electromagnetic waves, the thumb points in the direction of the electric field, the index finger points in the direction of the magnetic field, and the palm faces toward the direction of the wave's motion. (a) The thumb points to the right, and the index finger points up. According to the right hand rule, the electromagnetic wave is traveling out of the page. (b) The thumb points to the right, and the index finger points into the page. According to the right hand rule, the electromagnetic wave is traveling upward.