A plane electromagnetic wave propagating in the x-direction has wavelength of 6.0 mm. The electric field is in the y-direction and its maximum magnitude of 33 Vm^-1. The equation for the electric field as function of x and t is:

$33 \sin \pi \times 10^{11}(t-x / c)$

Angular frequency, $\omega=2 \pi c=\frac{2 \pi c}{\lambda} \quad[∵ v=c / \lambda]$

$=\frac{2 \pi \times 3 \times 10^8}{6 \times 10^{-3}}=\pi \times 10^{11} rad ~s^{-1}$

The equation for the electric field, along Y-axis in the electromagnetic wave is

$E_y=E_0 \sin \omega\left(t-\frac{x}{c}\right)=33 \sin \pi \times 10^{11}(t-x / c)$