A plane electromagnetic wave travelling along the +z direction, has electric field given byE_x=2\cos\left(\omega t\right)\;and\;E_y=2\cos\left(\omega t+90\right)^0
the wave is
(a) linearly polarized
(b) right circularly polarized
(c) left circularly polarized
(d) elliptically polarized
Ans : c)
We know that if the EM wave has two E components with the phase difference 90o then the polarization appear to be circular.
Consider the direction of propagation and coordinate axes as above. Then tip of Electric field is rotating anticlockwise or left circularly as shown in table below.