GATE Electronics and Communications (EC) 2015 Shift 2 Solved Paper

Two half – wave dipole antennas placed as shown in the figure are excited with sinusoidal varying current of frequency $3\mathit{M}\mathit{H}\mathit{z}$ and phase shift of π/2 between them (the element at the origin leads in phase.) If the maximum radiated E – field at the point P in the x-y plane occurs at an azimuthal angle of 60°, the distance $\mathit{d}$ (in meters) between the antennas is__________