Question

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

• A. ${10}^{-7}Wb$ $m^{-1}$
• B. $4\pi \times {10}^{-7}Wb$ $m^{-1}$
• C. $16{\pi }^2{10}^{-7}Wb$ $m^{-1}$
• D. $zero$

Answer 1

The correct option is A ${10}^{-7}Wb$ $m^{-1}$

$\oint \overrightarrow{B}\cdot d\overrightarrow{l}={\mu }_{0}I$
$=4\pi \times {10}^{-7}\times \frac{1}{4\pi }$
$={10}^{-7}Wb{m}^{-1}$