$A$ current of $10 \text{ A}$ flows through a horizontal straight wire $A$ with both ends rigidly fixed. Wire $B$ is placed directly above and parallel to $A$. The weight per unit length of wire $B$ is $40 \times 10^{-3} \text{ N/m}$ and it carries a current of $20 \text{ A}$. Find the distance of wire $B$ from wire $A$ so that wire $B$ remains at rest. Also,state the direction of current flowing through it.

• A
  $\frac{1}{3} \times 10^{-3} \text{ m}$,both are in same direction
• B
  $\frac{1}{2} \times 10^{-3} \text{ m}$,both are in opposite direction
• C
  $2 \times 10^{-3} \text{ m}$,both are in same direction
• D
  $1 \times 10^{-3} \text{ m}$,both are in opposite direction