The electric field and magnetic field of a plane electromagnetic wave propagating in vacuum are expressed as $E_x=E_0 \sin (kz - wt)$ Which of the following statements are correct? (A). The wave is propagating along the z- direction. Choose the correct answer from the options given below: |
(A), (B) and (D) only (A) and (B) only (A) and (C) only (A), (C) and (D) only |
(A) and (B) only |
The correct answer is Option (2) → (A) and (B) only Given: $E_x = E_0 \sin(kz - \omega t)$ and $B_y = B_0 \sin(kz - \omega t)$ (A) The wave propagates in the $+z$ direction because phase is $(kz - \omega t)$ → Correct. (B) $E$ is along $x$-axis, $B$ along $y$-axis, propagation along $z$-axis. They are mutually perpendicular → Correct. (C) $E$ and $B$ are perpendicular to each other but not parallel to propagation. They are both ⟂ to $z$ → Wrong. (D) Wave number $k = \frac{2\pi}{\lambda}$, not $\frac{\lambda}{2\pi}$ → Wrong. Correct statements: (A), (B) |