Q 12-04-048JEE MainJEE Main 2026 (28 Jan, Shift 1)Easy
The magnetic field at the centre of a current carrying circular loop of radius $R$ is $16\,\mu\text{T}$. The magnetic field at a distance $x = \sqrt3R$ on its axis from the centre is
______ $\mu\text{T}$.
Answer: (B) 2
$$B_{\text{axis}} = B_{\text{centre}}\left(\frac{R^2}{R^2+x^2}\right)^{3/2} = 16\left(\frac{R^2}{R^2+3R^2}\right)^{3/2} = 16\times\frac18 = 2\ \mu\text{T}$$
Solution by Sreeraj P, M.Sc Physics