Question 28: Magnetism and Matter

Question

Let $B_1$ be the magnitude of magnetic field at center of a circular coil of radius $R$ carrying current I. Let $\mathrm{B}_2$ be the magnitude of magnetic field at an axial distance ' $x$ ' from the center. For $x: \mathrm{R}=3: 4, \frac{\mathrm{~B}_2}{\mathrm{~B}_1}$ is :

Accepted Answer

$$\begin{aligned}
& B_1=\frac{\mu_0 i}{2 R} \quad \quad B_2=B_1 \sin ^3 	heta \
& 	herefore \frac{B_2}{B_1}=\sin ^3 	heta=\left(\frac{4}{5}ight)^3=\frac{64}{125}
\end{aligned}$$

Answer

$64: 125$

Answer

$25: 16$

Answer

$4: 5$

Answer

$16: 25$

Magnetism and Matter

Let B_1 be the magnitude of magnetic field at center of a circular coil of radius R carrying current I. Let \mathrm{B}_2 be the magnitude of magnetic field at an axial distance ' x ' from the center. For x: \mathrm{R}=3: 4, \frac{\mathrm{~B}_2}{\mathrm{~B}_1} is :

Choose the correct answer: