A long, straight wire carrying a current of 1.0A is placed horizontally in a uniform magnetic field B = 1.0 x 10-5T pointing vertically upward (figure 35-E1). Find the magnitude of the resultant magnetic field at the points P and Q, both situated at a distance of 2.0cm from the wire in the same horizontal plane.
μ0 = 4π × 10–7T-m/A
r = 2cm = 0.02m, I = 1A, vector B = 1 × 10–5T
We know: Magnetic field due to a long straight wire carrying current = μ0I/2πr
