JEE Mains · Physics · STD 12 - Electromagnetic waves
- JEE Mains 2019
- Medium
- MCQ
A plane electromagnetic wave travels in free space along the \(x -\) direction. The electric field component of the wave at a particular point of space and time is \(E =6\; Vm^{-1}\) along \(y -\) direction. Its corresponding magnetic filed component, \(B\) would be
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Answer & Solution
Correct Answer
(A) \(2 \times {10^{ - 8}}\,T\) along \(z -\) direction
Step-by-step Solution
Detailed explanation
The direction of propagation of an \(EM\) wave is direction of \(\overrightarrow{\mathrm{E}} \times \overrightarrow{\mathrm{B}}\) \(\hat{\mathrm{i}}=\hat{\mathrm{j}} \times \hat{\mathrm{B}}\)
\(\Rightarrow \hat{\mathrm{B}}=\hat{\mathrm{k}}\)
\(C=\frac{E}{B} \Rightarrow B=\frac{E}{C}=\frac{6}{3 \times 10^{8}}\)
\(\mathrm{B}=2 \times 10^{-8}\, \mathrm{T}\) along \(\mathrm{z}\) direction.
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