Physics · 2026
JEE Main · 21 January 2026, Shift 2 · Q39
An infinitely long straight wire carrying current I is bent in a planer shape as shown in the diagram. The radius of the circular part is r. The…
An infinitely long straight wire carrying current $\displaystyle I$ is bent in a planer shape as shown in the diagram. The radius of the circular part is $\displaystyle r$. The magnetic field at the centre $\displaystyle O$ of the circular loop is :
Official answer
From NTA’s final answer key for this paper.
(2)
$\displaystyle -\frac{\mu_0}{2 \pi} \frac{I}{r}(\pi-1) \hat{i}$
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JEE Main 2026 Physics question, with the answer from NTA’s final answer key. Where our answers come from.