UPSEE 2018 Solved Paper

Since, the current through two wires are from left to right, the magnetic field is directed outwards the plane of the paper. Also, current through the other two wires are from right to left, the magnetic field due to them is directed inwards the plane of the paper. Since, the value of current through all the wires is same and point P is equidistant from all the wires, the magnitude of magnetic fields are same. Hence, they are cancelled. So, the net magnetic field is zero.