Question

A square loop, carrying a steady current $I$, is placed in a horizontal plane near a long straight conductor carrying a steady current $I_1$ at a distance d from the conductor as shown in figure. The loop will experience

• A. a net repulsive force away from the conductor
• B. a net torque acting upward perpendicular to the horizontal plane
• C. a net torque acting downward normal to the horizontalplane
• D. a net attractive force towards the conductor

Answer 1

Answer: (D)

$F_{1} > F_{2}$ as $F \propto \frac{1}{d}$, and $F_{3}$ and $F_{4}$ are equal and opposite.
Hence, the net attraction force will be towards the conductor.