AIIMS 2018 Physics Magnetic Field due to Current MCQ Question

To find the magnetic field induction (B) at a point inside a long cylindrical wire carrying a current (I), we use Ampère's Law, which states $B = \frac{\mu_0 I}{2 \pi r}$, where $\mu_0 = 4\pi \times 10^{-7} \, \text{T m/A}$ is the permeability of free space and $r$ is the distance from the center of the wire. In this case, substituting $I = 10 \, \text{A}$ and $r = 0.002 \, \text{m}$ gives $B = \frac{4\pi \times 10^{-7} \times 10}{2\pi \times 0.002} = 1.6 \times 10^{-4} \, \text{T}$, confirming option A as correct. The other options are incorrect as they do not match the calculated value based on the given parameters and the application of Ampère's Law.