0.2A=?mA?uA

0.2A=?mA?uA

0.2A=200mA=200000uA

Some scientists believe that the earth's geomagnetic field is caused by the earth's (net) charge. Assuming that the earth's (net) charge is distributed on the surface, please briefly explain whether the earth's (net) charge is a positive charge or a negative charge according to the earth's rotation and the law of electromagnetism

Negative charge
The geomagnetic north pole is in the geographical North Pole, and the geomagnetic south pole is in the geographical North Pole. Therefore, the earth is regarded as an electrified solenoid. With the right hand, the direction of the current generating the geomagnetic field is from east to west. The direction of the earth's rotation is from West to East, opposite to the direction of the current. Therefore, the earth is negatively charged

According to the assumption of Ampere's rule, the magnetic field is generated by moving charges. If this idea is also applicable to the electromagnetic field, and there is no charge moving in a direction relative to the earth in the region at present, then it can be judged that the earth should
(with negative charge)
I hope to go on step by step

The earth turns from west to East
Then the charge also turns from west to East (relative geostationary)
The south pole is known as the N pole
According to the right hand rule, the positive charge moves from east to west
The earth is negatively charged

I would like to ask whether the formula of the force of magnetic field on moving charge was put forward by ampere?

No, it's Lorentz f Lo = bqv
Ampicillin: F = bil
It is to study the stress of the electrified wire in the magnetic field