A current-carrying wire consists of a circular arc joined to two radial straight portions that pass through the centre of curvature. Which statements about the field at the centre are correct?
Select all that apply

Question

A current-carrying wire consists of a circular arc joined to two radial straight portions that pass through the centre of curvature. Which statements about the field at the centre are correct?

G1 Physics · Accepted Answer

For each radial element, dℓ is parallel to the position vector toward the centre, so dℓ×r̂=0. Only the arc contributes, with B proportional to its angle.