Which of the following diagrams represent the veriation of electric field vector with time for a circularly polarised light

Options

A.
B.
C.
D.

Answer

A

Explanation

To form circularly polarised light
`E_(x)=E_(0)sin omega t`
`E_(y)=E_(0) cos omega t=E_(0) sin(omega t+(pi)/(2))`
where, `E_(0)` is amplitude.
Resultant amplitude
`|E|^(2)=E_(0)^(2)+E_(0)^(2)+2E_(0)*E_(0)"cos"(pi)/(2)`
`|E|=E_(0) sqrt(2)=` constant