Consider a plastic annulus of inner radius 4.40
cm and outer radius 12.00 cm. The charge on the
plastic annulus is uniformly distributed and amounts to a total of
(a) What is the charge density (a surface charge density) of the charged annulus?
(B) For this problem, let the origin of the coordinate system be at the center of the annulus with the y and z directions in the plane of the annulus. Find the x-component of the electric field at the location (17.70 cm, 0, 0) due only to a tiny piece of the annulus of area 0.0270 mm2 which is located at y = 8.200 cm and z = 0.
(C) Find the electric field strength on the axis of the annulus at a distance of 17.70 cm from the center of the annulus.
(d) Find the electric field strength on the axis of the annulus at a distance of 35.40 cm from the center of the annulus.
(E) Imagine replacing the annulus by a point charge of 25.0 uC located at what had been the center of the annulus. What would then be the electric field strength at the same location used in parts (b) and (c)?