A positively charged particle of 2 Coulombs is moving at 2 m/s in a magnetic field of strength 2 Tesla. The velocity is perpendicular to the magnetic field. The force acting on the charged particle will be?

Acircular ring of charge with radius b has total charge q uniformly distributed around it. what is the magnitude of the electric field at the center of the ring? 0 keq/b2 keq2/b2 keq2/b none of these answers