Question

Two long conductors separated by a distance `d` carry currents `I1` and `I2` in the same direction. They exerts a force F on each other. Now the current in one of them is increased two times and its direction is reversed. The distance is also increased to 3d, then the force between them is​

Answer 1

Explanation:

Force due to two current carrying conductor is given by,

F=2πdμ0I1I2l

F1=2π×3dμ0I1×2×I2l (direction is reversed)

F1=3−2F