A rigid wire consists of a semicircular portion of radius $R$ and two straight sections. The wire is partially immerged in a perpendicular magnetic field $B=B_0\ {j}$ as shown in figure. The magnetic force on the wire if it has a current $i$ is :
JEE MAIN 2024, Diffcult
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Note : $Direction of magnetic field is in$ $+\hat{k}$
$\vec{F}=i \vec{\ell} \times \vec{B}$
$\ell=2 \mathrm{R}$
$\vec{F}=-2 i R B \hat{j}$
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