Referring to the loop in the previous question, a straight thin wire with steady current flowing out of the plane of the paper is kept at the origin. Due to the presence of the current at the origin:
- AThe forces on and are zero.
- BThe forces on and are zero.
- CThe magnitude of the net force on the loop is .
- DThe magnitude of the net force on the loop is .
Solution & Step-by-step Explanation
The magnetic field produced by the wire at the origin is circular. At any point on the arcs and , the magnetic field vector is tangent to the arc. The current element of the loop along the arcs is also tangent to the arc.Since , the force .Thus, the forces on the arcs and are zero.