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The velocity of an electromagnetic wave is parallel to

Asked in NEET 2002 · Direction from E cross B, and oblique propagation

Answer: (2) ⃗E×⃗B

Step-by-step solution

The energy flow of an electromagnetic wave is given by the Poynting vector

⃗S=1/(μ₀)⃗E×⃗B, and the wave travels the way its energy goes.

So the velocity is parallel to ⃗E×⃗B.

Both fields are perpendicular to that direction, which is what makes the wave transverse.

Why the other options are wrong

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