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Physics · PYQ NEET UG 2023
हिन्दीA very long conducting wire is bent in a semi-circular shape from A to B as shown in figure. The magnetic field at point P for steady current configuration is given by :
Correct answer · Option 3
\( \frac{\mu_0 i}{4R} [1 - \frac{2}{\pi}] \) pointed into the page
Explanation
The magnetic field at the center P is due to the straight wire and the semi-circular arc. By superposition and right-hand rule, \( B = \frac{\mu_0 i}{2\pi R} - \frac{\mu_0 i}{4R} = \frac{\mu_0 i}{4R}[\frac{2}{\pi} - 1] \) pointed into the page, or using magnitude with direction: \( \frac{\mu_0 i}{4R}[1 - \frac{2}{\pi}] \) pointed into the page.
