# Magnetic field and magnetic force

1. The problem statement, all variables and given/known data
PHYSICS MAGNETIC FIELD
two long parallel straight wire are seperated by a distance r in vacuum. an electric current flow through each wire in opposite direction, the magnetic flux density at the centre between 2 wires is (2)(ε0)/(πr) (ANS FROM BOOK) … can someone explain why?

my ans would be 0.5x2x(ε0)/(πr)… because the resultant between 2 wires is repulsive force…

2. Relevant equations

3. The attempt at a solution

http://ift.tt/1hpWHHa
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