What do we calculate if we integrate length element ds aroun

What do we calculate if we integrate length element ds around a full circle?

Which currents are included in a calculation of Ampere’s law?

Which describes the magnetic field at a point inside a long wire that carries current uniformly across its circular cross-sectional area?

Solution

A

circumference of circle

B

only currents that are inside the loop of integration

C

The field is tangent to a circle through the point and concentric with the wire