Two short magnets of equal dipole moments M are fastened perpendicularly at their centre (figure). The magnitude of the magnetic field at a distance d from the centre on the bisector of the right angle is

Resultant magnetic moment of the two magnets isMnet=M2+M2=2MImagine a short magnet lying along OP with magnetic moment equal to 2M. Thus point P lies on the axial Iine of the magnet.∴ Magnitude of magnetic field at P is given byB=μ04π22Md3