Magnetic Effects Of Current Question 11
Question 11 - 2024 (31 Jan Shift 1)
A rigid wire consists of a semicircular portion of radius $\mathrm{R}$ 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) $-\mathrm{iBR} \hat{\mathrm{j}}$
(2) $2 \mathrm{iBR} \hat{\mathrm{j}}$
(3) iBR $\hat{j}$
(4) $-2 \mathrm{iBR} \hat{\mathrm{j}}$
Show Answer
Answer: (4)
Solution:
Note : Direction of magnetic field is in $+\hat{k}$
$\overrightarrow{\mathrm{F}}=\mathrm{i} \vec{\ell} \times \overrightarrow{\mathrm{B}}$ $\ell=2 \mathrm{R}$
$\vec{F}=-2 \mathrm{iRB} \hat{j}$
