Exercise E3 Magnetic Field Lines
(written test, approx. 6 % of a 120-minute written test, SS2024)
The following setup shall be given:
- Four conductors are located perpendicular to the plane of the diagram
- All of them conduct a current with the same magnitude, but not in the same direction.
- A permanent magnet is located in between the conductors.
1. Do not consider the permanent magnet at first. Draw at least 10 field lines of the H-field qualitatively. Give a a correct representation of their direction, and density for the shown area.
2. Discuss how the permanent magnet affects the H-field, based on the fundamental definition of the H-field.
- The H-field is defined by currents $\sum I = \int H {\rm d}s$ .
- In the permanent magnet, there are no free currents.
- The bound currents (of the permanent magnet) create also an H field.
- This exits on the north pole and enters the magnet on the south pole (similar to the B-field)_
- $H = B/\mu$
- The H-field from task 1 gets distracted
