Chapter 15: Q4Q (page 616)
A rod with uniformly distributed charge is long. We need to calculate at a distance of from the midpoint of the rod. Which equation for the electric field of a rod should we use? (1) Exact, (2) Approximate, (3) Either exact or approximate, (4) Neither—we have to do it numerically, (5) Neither—we need to integrate.
Short Answer
The approximate equation can be used.