รบกวนช่วยเฉลยให้ทีนะค่ะหรือแนะทางให้ก็ได้ คิดไม่ออกจริงๆ เป็นโจทย์ข้อสอบเก่าฟิสิกส์ของ TU-Dortmund ค่ะ โจทย์มีอยู่ว่า
ข้อ1. A horizontal stored bar magnet with well-known magnetic moment

=31.75 Am
2 is aligned perpendicularly to the earth's magnetic field and with one in dipole direction in was away z compass needle present the direction of the resulting magnetic field B determined, which from H
E of the earth's magnetic field and the component H
S of the bar magnet in dipole direction results the ground distance. How large is H
E, if at distance z = 50cm the compass needle were away around

is expenditure-steered? The field the bar magnet is to be treated as dipole field.
ข้อ2. In a thread jet pipe electrons, which rests from by a tension U
B=1kV was accelerated, are forced by a homogeneous magnetic field B=10mT on a circular path. Compute they the radius of the circular path, and determine them the direction of rotation.