Two long parallel wires P and Q are held perpendicular to the plane of the paper at a separation of 5m. If P and Q carry currents of 2.5 A and 5 A respectively in the same direction, then the magnetic field at a point midway between P and Q is

When the current flows in both wires in the same direction then magneticfield at half way due to the wire P, B→p=μ0I12π52=μ02.5π5=μ02π(⊗)Magnetic field at half way due to wire Q,B→Q=μ0I22π52=μ05π5=μ0π(⊙)Net magnetic field at half way,B→=B→P+B→Q=−μ02π+μ0π=μ02π(⊙)