The wire ABC shown in figure forms an equilateral triangle. Find the magnetic field B at the centre O of the triangle assuming the wire to be uniform.

Question

Philoid · Accepted Answer

Let current 2I flow through the circuit.
Since the wire is uniform, the current will enter the loop at point A and divide equally between the two arms AB and AC (as shown in the figure)

Now,
Magnetic field induced at point P due to wire AB and wire AC = B (say)
(Perpendicular to the plane in outward direction)

Magnetic field at P due to wire BD and DC = B' (say)
(Perpendicular to the plane in outward direction)

∴ Net magnetic field at = 0