Two wires 1 and 2 carrying currents $i_1$, and $i_2$ respectively are shown in the figure given below,
Force on wire 2 -due to $B$, (field of wire 1 ) is given by
$F_{2}=i_{2} lB_{1}$
Using right hand screw rule, direction of $F_{2}$ would be towards wire 1 .
Similarly, force on wire due to $B_{2}$ (field of wire 2)
$F_{1}=\dot{i}_{1} B _{2}$
Again, by using right hand screw rule,
direction of $F_{1}$ would be towards wire 2 .
If two parallel conductors carry (equal or unequal) current in the same direction, they will exerted force towards each other i.e., they will be attract each other.
