Two polarisers \( P_1 \) and \( P_2 \) are placed in such a way that the intensity of the transmitted light will be zero. A third polariser \( P_3 \) is inserted in between \( P_1 \) and \( P_2 \), at particular angle between \( P_2 \) and \( P_3 \). The transmitted intensity of the light passing the through all three polarisers is maximum. The angle between the polarisers \( P_2 \) and \( P_3 \) is: