Question

Two long straight parallel conductors A and B, kept at a distance r, carry current I in opposite directions. A third identical conductor C, kept at a distance `(r/3)` from A carry current I₁ in the same direction as in A. The net magnetic force on unit length of C is ______.

पर्याय

• `(3 mu_0 I I_1)/(2 pi r)`, towards A

• `(3 mu_0 I I_1)/(2 pi r)`, towards B

• `(3 mu_0 I I_1)/(4 pi r)`, towards A

• `(3 mu_0 I I_1)/(4 pi r)`, towards B

Answer 1

Two long straight parallel conductors A and B, kept at a distance r, carry current I in opposite directions. A third identical conductor C, kept at a distance `(r/3)` from A carry current I₁ in the same direction as in A. The net magnetic force on unit length of C is `bbunderline((3 mu_0 I I_1)/(2 pi r), "towards A")`.

Explanation:

The force between two parallel current-carrying conductors per unit length is given as `F = mu_0/(4 pi) * (2 I_1 I_2)/r`

In the arrangement given below

Net magnetic force on unit length of C,

`F_(CA) = mu_0/(4 pi) * (2 I I_1)/(r/3) = (3 mu_0 I I_1)/(2 pi r)`, towards A as current is flowing in same didirectionn both wires A and C.