A system of three polarizers P_1, P_2, P_3 is set up such that the pass axis of P_3 is crossed with respect to that of P_1. The pass axis of P_2 is…

A system of three polarizers $\displaystyle \mathrm{P}_1, \mathrm{P}_2, \mathrm{P}_3$ is set up such that the pass axis of $\displaystyle \mathrm{P}_3$ is crossed with respect to that of $\displaystyle P_1$. The pass axis of $\displaystyle \mathrm{P}_2$ is inclined at $\displaystyle 60$° to the pass axis of $\displaystyle \mathrm{P}_3$. When a beam of unpolarized light of intensity $\displaystyle \mathrm{I}_{\mathrm{o}}$ is incident on $\displaystyle \mathrm{P}_1$, the intensity of light transmitted by the three polarizers is I . The ratio $\displaystyle \left(\mathrm{I}_{\mathrm{o}} / \mathrm{I}\right)$ equals (nearly) :