MCQ

Share

An electromagnetic wave with frequency $\omega $ and wavelength $\lambda $ travels in the $+y$ direction. Its magnetic field is along $+x$ axis. The vector equation for the associated electric field (of amplitude $E_0$) is

• A
  $\vec E = {E_{0\,}}\,\cos \left( {\omega t - \frac{{2\pi }}{\lambda }y} \right)\hat x$
• B
  $\vec E = -{E_{0\,}}\,\cos \left( {\omega t + \frac{{2\pi }}{\lambda }y} \right)\hat x$
• C
  $\vec E = -{E_{0\,}}\,\cos \left( {\omega t + \frac{{2\pi }}{\lambda }y} \right)\hat z$
• ✓
  $\vec E = {E_{0\,}}\,\cos \left( {\omega t - \frac{{2\pi }}{\lambda }y} \right)\hat z$