The degree of polarization of partially polarized light is `P = 0.25`. Find the ratio of intensities of the polarized component of this light and the natural component.

Explanation

Suppose the partially polarized consists of natural light of intensity `I_(1)` and plane polarized light of intensity `I_(2)` with direction of vibration parallel to, say, `x-axis`.
Then when a polaroid is used to transmit, it the light transmitted will have a maximum intensity
`(1)/(2)I_(1) + I_(2)`,
when the principle direction of the polaroid is parallel to `x-`axis, and will ahve a minimum intensity `(1)/(2)I_(1)` when the principle direction is `_|_^(r )` to `x`-axis.
Thus `P = (I_(max) - I_(min))/(I_(max) + I_(min)) = (I_(2))/(I_(1) + I_(2))`
so `(I_(2))/(I_(1)) = (P)/(1- P) = (0.25)/(0.75) = (1)/(3)`.