Q131 / 200 · NEET 2022 (Phase 2) · Physics
The magnetic field on the axis of a circular loop of radius $100 \mathrm{~cm}$ carrying current $I=\sqrt{2} \mathrm{~A}$, at point $1 \mathrm{~m}$ away from the centre of the loop is given by:
- Correct answerA$3.14 \times 10^{-7} \mathrm{~T}$
- B$6.28 \times 10^{-7} \mathrm{~T}$
- C$3.14 \times 10^{-4} \mathrm{~T}$
- D$6.28 \times 10^{-4} \mathrm{~T}$
Solution
As per question, we have;
$\begin{aligned}
\mathrm{B} & =\mathrm{B}_0 \sin ^3 \theta \\
& =\frac{\mu_0 \mathrm{I}}{2 \pi} \sin ^3\left(45^{\circ}\right) \\
& =\frac{4 \pi \times 10^{-7} \times \sqrt{2}}{2 \times 1}\left(\frac{1}{\sqrt{2}}\right)^3 \\
& =3.14 \times 10^{-7} \mathrm{~T}
\end{aligned}$
Hence, the correct answer is option: 'A'.