Two short magnets of equal dipole moments M are fastened perpendicularly at their centres figure. The magnitude of the magnetic field at a distance d from the centre on the bisector of the right angle is
We know that the resultant magnetic field on a point P due to a dipole can be expressed as,
Where, M is the magnetic moment, r is the perpendicular distance of the point P from the centre of the dipole. Θ is the angle made by the line connecting the centre and the point P with that of axis of the dipole.
In the given question, as the point is on the angular bisector of the right angle, Θ is 45° . Hence the above expression becomes,
Or,
Here the point P will affected by both the crossed dipoles, hence the total magnetic field will be,
Or,
Or,
Thus, option C is the correct option.