Question 78: Magnetism and Matter

Question

As shown in the figure, a long straight conductor with semicircular arc of radius $$\frac{\pi}{10}$$m is carrying current $$\mathrm{I=3A}$$. The magnitude of the magnetic field, at the center O of the arc is :
(The permeability of the vacuum $$=4\pi	imes10^{-7}~\mathrm{NA}^{-2}$$)

Accepted Answer

Magnetic field due to two straight wire will be zero as point O is on the axis of the wire. Magnetic field at $B$ will be only due to the semicircular arc.
$$
 \begin{aligned}
	ext { So, } B & =\left(\frac{\mu_0 i}{4 r}ight)=\frac{\left(4 \pi 	imes 10^{-7}ight) 	imes 3}{4 	imes\left(\frac{\pi}{10}ight)} \\
& =3 	imes 10^{-6} \mathrm{~T} \\
& =3 \mu \mathrm{T}
\end{aligned}
$$

Answer

$$4\mu\mathrm{T}$$

Answer

$$3\mu\mathrm{T}$$

Answer

$$6\mu\mathrm{T}$$

Answer

$$1\mu\mathrm{T}$$

Magnetism and Matter

As shown in the figure, a long straight conductor with semicircular arc of radius $\frac{\pi}{10}m is carrying current \mathrm{I=3A}. The magnitude of the magnetic field, at the center O of the arc is : (The permeability of the vacuum =4\pi\times10^{-7}~\mathrm{NA}^{-2}$)

Choose the correct answer: