`A, B` and `C` are parallel conductors of equal length carrying currents `I, I` and `2I` respectively. Distance between `A` and `B` is `x`. Distance between `B` and `C` is also `x`. `F_(1)` is the force exerted by `B` on `A` and `F_(2)` is the force exerted by `B` on `c`. Choose the correct answer

Options

A. `F_(1)=2F_(2)`
B. `F_(2)=2F_(1)`
C. `F_(1)=F_(2)`
D. `F_(1)=-F_(2)`

Answer

D

Explanation

`F=(mu_(0))/(4pi)(2i_(1)i_(2))/(a)`
`F_(1)=(mu_(0))/(4pi)=(2i^(2))/(x)` (Attraction)
`F_(2)=(mu_(0))/(4pi)=(2ixx2i)/(2x)=(mu_(0))/(4pi)(2i^(2))/(x)` (Repulsion)
Thus `F_(1)=-F_(2)`