$3)$ Too much force in my circuit $(10$ pts$)$ You are worried that you may have too much magnetic force between parallel current vias $($essentially straight$-$line segments of current$)$ in your circuit board. The vias will be damaged if the magnetic force per unit length exceeds $0\mathrm{.}25$ N$/$m$.$ The currents are $10$A$,$ the vias are $0\mathrm{.}1$ mm apart, and the current runs in opposite directions in the two lines. a$)$ Is the force between the vias attractive or repulsive? $(4$ pts$)$ b$)$ Do you need to worry about damaging the current vias? What is the force per unit length on the vias? $(6$ pts$)$