Two long conductors, separated by a distance `d` carry current `I_(1) and I_(2)` in the same direction . They exert a force `F` on each other. Now the current in one of them is increased to two times and its direction is reversed . The distance is also increased to `3d`. The new value of the force between them is

Options

A. `-2F`
B. `F//3`
C. `2F//3`
D. `-F//3`

Answer

C

Explanation

`F prop (i_(1)//i_(2))/(a)`, Since one of the current increase two times and distance increases three times, so force become `(2)/(3)` times. Also due to the reversal of direction current force negative.