Question-02 Two very long straight conductors (wires) are set parallel to each other. Each carries a current ‘I’ in the same direction and the separation between them is ‘2r’. The intensity of the magnetic field at point ‘P’ (as shown in the figure) (\mu_0 = permeability of free space) is
(A) \frac{2\mu_0 I}{3\pi r}
(B) \frac{3\mu_0 I}{8\pi r}
(C) \frac{\mu_0 I}{4\pi r}
(D) \frac{\mu_0 I}{2\pi r}
Answer : (A)
Explanation:
In the figure, magnetic field at point P is given by,
B_{net}=B_1+B_2 =\frac{\mu_0 I}{2\pi}\times\left(\frac{1}{r}+\frac{1}{3r}\right) =\frac{\mu_0 I}{2\pi}\times\left(\frac{4}{3r}\right) =\frac{2\mu_0 I}{3\pi r}