• # question_answer 45) A current of $(1/4\pi )$ampere is flowing in a long straight conductor. The line integral of magnetic field around a closed path enclosing the current carrying conductor is: A) ${{10}^{-7}}$ weber per meterB) $4\pi \times {{10}^{-7}}$ weber per meterC) $16{{\pi }^{2}}\times {{10}^{-7}}$weber per meterD)  0

By Amperes Law, we get, $\vec{B}.\overrightarrow{dl}={{\mu }_{0}}I=4\pi \times {{10}^{-7}}\times \frac{1}{4\pi }={{10}^{-7}}\,w/{{m}^{2}}$ Hence, the correction option is [a].