Calculate the force per unit length on a long straight wire carrying current `4A` due to parallel wire carrying current `6A` current. Distance between the wires `=3cm`.

Explanation

Here `I_(1)=4A`,
`I_(2)=6A`
r=3cm = 0.03 cm
Now force per unit length is
`F=(mu_(0))/(4pi).(2I_(1)I_(2))/(r ) implies F=10^(-7) xx(2xx4xx6)/(0.03)=1.6xx10^(-4) Nm^(-1)`.