Topic: Electromagnetic Phenomena and Theorems
I need to knw as much as possible of currents along the surface of a sphere, in physics, to implement hairy ball theorem comprehensively for the case of 1 vanishing vector filed point called hairy ball hole.

Topic: Electromagnetic Phenomena and Theorems
A circular ring of radius 𝑅 = 0.75 𝑚 has a net charge of 𝑄 = +275 𝜇𝐶, which is uniformly
distributed along the ring. A point charge of 𝑞 = −75 𝜇𝐶 is placed at the center of the ring.
Find the magnitude of the net force exerted on the point charge by the ring.