In a travelling plane electromagnetic wave in vacuum, the electric and magnetic fields at the same point are:
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Question

In a travelling plane electromagnetic wave in vacuum, the electric and magnetic fields at the same point are:

G1 Physics · Accepted Answer

For a plane electromagnetic wave, E = E₀ cos(kx − ωt) and B = B₀ cos(kx − ωt). Both fields contain the same phase factor. Hence their maxima, minima and zero crossings occur simultaneously. Therefore E and B are in phase. Correct option: C.