일반물리학 2 — Electric Potential: Problem 5

5 (a) Figure 24-25a shows a nonconducting rod of length \(L = 6.00\text{ cm}\) and uniform linear charge density \(\lambda = +7.07\text{ pC/m}\). Assume that the electric potential is defined to be \(V = 0\) at infinity. What is \(V\) at point \(P\) at distance \(d = 8.00\text{ cm}\) along the rod's perpendicular bisector? (b) Figure 24-25b shows an identical rod except that one half is now negatively charged. Both halves have a linear charge density of magnitude \(3.68\text{ pC/m}\). With \(V = 0\) at infinity, what is \(V\) at \(P\)? Is the potential at \(P\) positive, negative, or zero if \(P\) is moved in the plane of the figure by a distance of \(L/4\) (c) upward and (d) leftward?