posted by jenish .
The Earth has an electric field with magnitude roughly 100 N/C at its surface.
A) Assuming there is a point charge at the earth's center creating this field, how much charge does the earth posses? Treat the earth as a sphere of radius 6.37 * 10^6 m.
B)As the earth orbits the sun,this charge moves and therefore creates a magnetic field. If we assume the earth moves on a circle ( whihc is approximately true) we can use the eqn for a current loop, B =(miu)I/2R, to find the magnetic field created by the earth( by the way, this is completely unrelated to the earth's North and south magnetic poles!) but first, find the current created by the earth as ut circles the sun.
HINT: I= Q/(delta)t. Think of a cross section of the earth' orbit. How often does a charge pass through it?
C) Using the earth sun distance , R= 1.5 * 10^11 m, calculate the magnetic field created by earth as it circles the sun.