Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance of 5m between them. If P and Q carry current of 5A and 2.5A respectively in the same direction, then the magnetic field at a point halfway between the wires is

When current flow in both wire in same direction then  magnetic field at half way due to P wire. B→P=μ0I12π52=μ0I1π5=μ0π ( where I1=2.5Amp) The direction of Bp is downward ⊗ Magnetic field at half way due to Q wire B→Q=μ0I22π52=μ02π[ upward ⊙][whereI2=2.5Amp.] Net magnetic field at half way B→=B→P+B→Q=μ0π−μ02π=μ02π(downward ⊗)