Magnetic Effects Of Current Question 11
Question 11 - 2024 (31 Jan Shift 1)
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 $B=B _0 \hat{j}$ as shown in figure. The magnetic force on the wire if it has a current $i$ is :
(1) $-iBR \hat{j}$
(2) $2 iBR \hat{j}$
(3) iBR $\hat{j}$
(4) $-2 iBR \hat{j}$
Show Answer
Answer: (4)
Solution:
Note : Direction of magnetic field is in $+\hat{k}$
$\overrightarrow{F}=i \vec{\ell} \times \overrightarrow{B}$ $\ell=2 R$
$\vec{F}=-2 iRB \hat{j}$
