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Moving Charges and Magnetism — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsMoving Charges and Magnetism3 Marks
Question
A circular loop of radius a, carrying a current i, is placed in a two-dimensional magnetic field. The centre of the loop coincides with the centre of the field The strength of the magnetic field at the periphery of the loop is B. Find the magnetic force on the wire.
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Answer


$\text{l}=2\pi\text{a}$
Magnetic field $=\overrightarrow{\text{B}}$ radially outwards
Current ⇒ 'i'
$\text{F}=\text{i l}\times\text{B}$
$=\text{i}\times(2\pi\text{a}\times\overrightarrow{\text{B}})$
$=2\pi\text{ai B}$ perpendicular to the plane of the figure going inside.

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