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

`Fprop(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 becomes negative.