JEE Mains · Physics · STD 12 - 8. Electromagnetic waves
An electromagnetic wave is represented by the electric field \(\vec E = {E_0}\hat n\,\sin \,\left[ {\omega t + \left( {6y - 8z} \right)} \right]\). Taking unit vectors in \(x, y\) and \(z\) directions to be \(\hat i,\hat j,\hat k\) ,the direction of propogation \(\hat s\), is
- A \(\hat S = \left( {\frac{{ - 3\hat j + 4\hat k}}{5}} \right)\)
- B \(\hat S = \left( {\frac{{ 4\hat j - 3\hat k}}{5}} \right)\)
- C \(\hat S = \left( {\frac{{ - 4\hat k + 3\hat j}}{5}} \right)\)
- D \(\hat S = \left( {\frac{{ - 3\hat i - 4\hat j}}{5}} \right)\)
Answer & Solution
Correct Answer
(A) \(\hat S = \left( {\frac{{ - 3\hat j + 4\hat k}}{5}} \right)\)
Step-by-step Solution
Detailed explanation
\(\overrightarrow{\mathrm{E}}=\mathrm{E}_{0} \hat{\mathrm{n}} \sin \left(\omega \mathrm{t}+(6 \mathrm{y}-8 \mathrm{z})=\mathrm{E}_{0} \hat{\mathrm{n}} \sin (\omega \mathrm{t}+\overrightarrow{\mathrm{k}} \cdot \overrightarrow{\mathrm{r}})\right.\) where…
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