Two Polaroids \[{{P}_{1}}\]and\[{{P}_{2}}\]are placed with their axis perpendicular to each other. Un polarised light \[{{l}_{0}}\]is incident on\[{{P}_{1}}.\]A third polaroid\[{{P}_{3}}\]is kept in between\[{{P}_{1}}\]and\[{{P}_{2}}\]such that its axis makes an angle\[{{45}^{o}}\]with that of\[{{P}_{1}}.\]The intensity of transmitted light through\[{{P}_{2}}\] is