Indicate the signals used for unpolarised,polarised,and partially polarised light.

(N/A) The signal with $\vec{E}$ vectors parallel to the page for plane-polarised light is shown in figure $(a)$.
The signal with $\vec{E}$ vectors perpendicular to the page for plane-polarised light is shown in figure $(b)$.
Unpolarised light signals are shown in two ways in figure $(c)$,where $(i)$ represents the light propagating along the axis with vibrations in all directions in the plane perpendicular to the direction of propagation,and $(ii)$ shows the combination of vertical and horizontal components.
The signal for partially polarised light is shown in figure $(d)$,which indicates an unequal distribution of vibrations in different directions.