For a plane electromagnetic wave propagating in x -direction, which one of the following combination gives the correct possible directions for electri - Physics MCQ NEET 2021 2026 | ExamTest.live

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For a plane electromagnetic wave propagating in x -direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

Solution & Step-by-step Explanation

The direction of propagation of an electromagnetic wave is given by the vector product E \times B .Given the propagation is in the x -direction (\hat{i}).For Option D: E = - \hat{j} + \hat{k} B = - \hat{j} - \hat{k} E \times B = (- \hat{j} + \hat{k}) \times (- \hat{j} - \hat{k}) = (- \hat{j} \times - \hat{j}) + (- \hat{j} \times - \hat{k}) + (\hat{k} \times - \hat{j}) + (\hat{k} \times - \hat{k}) = 0 + \hat{i} + \hat{i} + 0 = 2 \hat{i} The direction is along the + x axis.

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For a plane electromagnetic wave propagating in x -direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

\hat{j} + \hat{k}, \hat{j} - \hat{k}

- \hat{j} + \hat{k}, - \hat{j} + \hat{k}

\hat{j} + \hat{k}, \hat{j} + \hat{k}

- \hat{j} + \hat{k}, - \hat{j} - \hat{k}

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