A thin ring of radius carries a charge spread uniformly around it
PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Electrostatic fields and potential · Electrostatic fields and potential
Electricity, Magnetism and Electromagnetism, Ch Electric charge, Coulomb's law and the electric field
Problem
A thin ring of radius R=5.00cm carries a charge Q=+8.00nC spread uniformly around it. The ring lies in the xy-plane with its centre at the origin, so its axis is the z-axis. A point charge q1=−4.00nC is held at the centre of the ring. Everything is in vacuum, all of these charges are held fixed, and the ring's charge stays uniformly spread.
((a)) Find the magnitude and direction of the electric field at the point P on the axis at z=+12.0cm.
((b)) A small charge q0=+2.00nC is now placed at P. Find the magnitude and direction of the force on it.