A plane electromagnetic wave travels along the +x-axis in free space. Which condition is impossible for the wave?
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Question

A plane electromagnetic wave travels along the +x-axis in free space. Which condition is impossible for the wave?

G1 Physics · Accepted Answer

A plane electromagnetic wave in free space is transverse. For propagation along +x, both E and B must be perpendicular to the x-axis. Therefore a non-zero longitudinal electric-field component Eₓ is impossible for an ideal plane electromagnetic wave. Correct option: C.