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Model Paper 2 — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsModel Paper 21 Mark
MCQ
Current carrying loop of radius $r$ is placed normal to uniform magnetic field $\overrightarrow{ B }$. If current flowing is $I$, then magnetic force acting on it will be __________ .
  • A
    Ir $\overrightarrow{ B }$
  • B
    $2 \pi r I \overrightarrow{ B }$
  • C
    zero
  • D
    $\pi r^2 IB$
✓

Answer

C. zero
$\rightarrow$ Axis of loop and magnetic field are parallel. Hence, $\theta=0^{\circ}$
$\begin{array}{l}
\therefore F=BI / \sin \theta, \sin 0^{\circ}=0 \\
\therefore F=0
\end{array}$

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