Q.
Two wires with currents 2 A$\ $and $1$ A are enclosed in a circular loop. Another wire with current 3 A is situated outside the loop as shown. The $\oint_{}^{}{\overrightarrow{B}.d\overrightarrow{l}}$ around the loop is
A) $\mu_{0}$
B) 3$\mu_{0}$
C) 6$\mu_{0}$
D) 2$\mu_{0}$
Explanation
(a) According to Ampere’s circuital law
$\oint_{}^{}{\overrightarrow{B}.d\overrightarrow{l}} = \mu_{0}I_{enclosed} = \mu_{0}\lbrack 2A - 1A\rbrack = \mu_{0}$
Since currents $2A$ and $1A$ are in the opposite direction
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.