4 views

A plane eelctromagnetic wave travelling along $+z$ - direction, has its electric field given by $\mathrm{E}_{x}=2 \cos \left({ }^{*} t\right)$ and $\mathrm{E}_{y}=2 \cos \left({ }^{*} t+90^{\circ}\right)$.
The wave is

1. linearly polarised
2. right circularly polarised
3. left circularly polarised
4. elliptically polarised