Q 12-04-084JEE MainJEE Main 2024 (27 Jan, Shift 1)Easy
Two long, straight wires carry equal currents in opposite directions as shown in figure. The separation between the wires is $5.0\ \text{cm}$. The magnitude of the magnetic field at a point P midway between the wires is ______ $\mu\text{T}$. (Given: $\mu_0 = 4\pi\times10^{-7}\ \text{T m A}^{-1}$)
Numerical value type. Enter your answer.
Answer: 160
Each wire is $2.5\ \text{cm}$ from P. For opposite currents, the fields at a point between the wires point in the same direction, so they add:
$$B = 2\times\frac{\mu_0 I}{2\pi d} = 2\times\frac{2\times10^{-7}\times10}{0.025} = 2\times8\times10^{-5} = 1.6\times10^{-4}\ \text{T} = 160\ \mu\text{T}$$
Solution by Sreeraj P, M.Sc Physics