Question

A current of $\frac{1}{4\pi }A$ is flowing in a long straight conductor. The line integral of magnetic induction around a closed path enclosing the current carrying conductor is:

• A. $4\pi \times {10}^{-7}Wb/m$
• B. ${10}^{-7}Wb/m$
• C. $16\pi \times {10}^{-7}Wb/m$
• D. $0$

Answer 1

The correct option is B ${10}^{-7}Wb/m$

Using ampere's circuital law,
The line integral of magnetic field in a closed loop equals ${\mu }_{0}i$ , where i is the current enclosed by the loop
$\varphi Bide={\mu }_{0}i$
$={\mu }_0\times \frac{1}{4\pi }$
$={10}^{-7}Wb/m$