Question 1 : A charge of 3.00 pC is uniformly distributed on a ring of radius 10 cm. Find the electric field strength on the axis at distances of (a) 1.0 cm, (b) 10.0 cm, and (c) 5.0 m from the center of the ring. (d) Find the field strength 5.0 m using the approximation that the the ring is a point charge at the origin, and compare your results for parts (c) and (d). Is your approximation a good one? Explain your answer.
Question 2 : Show that the electric field strength E on the axis of a ring charge of radius R has maximum values at z = IRRa What is this maximum value of E?