I just had a quick thing i wanted to clarify... The question was: If u have two horizontal parallel current carrying wires 196 cm apart, with the bottom wire carrying a current of 2.2 A to the west and the top 1.1 A to the west, what is the magnetic field at the point P? Point P being the midpoint between the 2 wires. What I thot you would do is just find the 2 separate B-fields due to each wire and then add them. However, the answer in the book says that it is just the field due to bottom wire. I was wondering why this is and how come otherwise we add the fields, or subtract depending on the current direction.