Question 30 of 276
A current of 5A exists in a square loop of side . Then the magnitude of the magnetic field at the centre of the square loop will be . where, value of p is _____ .
Take .
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Answer: 8

Let B be the magnetic field due to single side
$\begin{aligned}
& \text { then } B=\frac{\mu_0 \mathrm{i}}{4 \pi \mathrm{~d}}\left(\sin \theta_1+\sin \theta_2\right) \\
& =\frac{10^{-7} \times 5 \times 2}{\frac{1}{2 \sqrt{2}}} \times \frac{1}{\sqrt{2}}=2 \times 10^{-6} \\
& \therefore B_{\text {net }} \text { at centre } O=4 B \\
& =8 \times 10^{-6}
\end{aligned}$
