Correct Answer - B
According to law of Malus, when a beam of complately plane polarised light is incident on an analyser, the resulant intensity o flight `(I)` transmitted from the analyser varies directly as the square of the cosine of the angle `(theta)` between planes of transmission of analyser and polariser.
i.e., `I prop cos^(2) theta`
and `I = I_(0) cos theta` ..(i)
where `I_(0) =` intensity of the light from polariser.
From Eq. (i), we note that if the transmission axes of polariser and analyser are parallel (i.e., `theta = 0^(@)` or `180^(@)`), then `I = I_(0)`. it means that intensity of transmitted light is maximum. when the transmission axes of polariser and analyser are perpendicular (i.e, `theta = 90^(@)`), then `I = I cos ^(2) 90^(@) = 0`. It means the intensity of transmitted light is minimum.
On plotting a graph between `I` and `theta` as givwn by relation (i), we get the curve as shown in figure.