MCQ
A mathematical representation of electromagnetic wave is given by the two equations $E = E_{max}\,\, cos (kx -\omega\,t)$ and $B = B_{max} cos\, (kx -\omega\,t),$ where $E_{max}$ is the amplitude of the electric field and $B_{max}$ is the amplitude of the magnetic field. What is the intensity in terms of $E_{max}$ and universal constants $μ_0, \in_0.$
  • A
    $I=\frac{1}{2}\sqrt {\frac{\mu_0}{\in_0}E^2_{max}}$
  • $I=\frac{1}{2}\sqrt {\frac{\in_0}{\mu_0}E^2_{max}}$
  • C
    $I=2\sqrt {\frac{\mu_0}{\in_0}E^2_{max}}$
  • D
    $I=2\sqrt {\frac{\in_0}{\mu_0}E^2_{max}}$

Answer

Correct option: B.
$I=\frac{1}{2}\sqrt {\frac{\in_0}{\mu_0}E^2_{max}}$
b

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