Two long and parallel stright A and B carrying currents of `8.0A and 5.0A` in the same direction are separted by a distance of `4.0cm`. Estimate the force on a 10 cm section of wire A.

Explanation

We know that, `(F)/(l)=(mu_(0)I_(1)I_(2))/(2pir) or, F=(mu_(0)I_(1)I_(2))/(2pir)*l`
`:.F=(4pixx10^(-7)xx8xx5)/(2pixx4xx10^(-2))xx10xx10^(-2)=2xx10^(-5)N`
(attractive force is towards A to B along the perpendicular)