1. The problem statement, all variables and given/known data A current I is flowing in a square wire loop of side a. Find the approximate value of the magnetic field intensity magnitude at the point P, which is near to one of the corners in the plane of the square at the same d distance from the near two sides! (d<<a). 2. Relevant equations I would guess biot and savarts law or formula of magnetic field on a straight current carrying conductor. 3. The attempt at a solution I thought like this: B=2*I*u0/(2*pi*d)=2I*u0/(pi*d). That would be twice the magnetic field of an infinite long current conducting wire. But that was wrong and I don't know why.. Any help would be greatly appretiated.