試題詳解

26.A charge per unit length given by λ(x) = bx, where b = 12 nC/m², is distributed along the  x axis from x = +9.0 cm to x = +16 cm. If the electric potential at infinity is taken to be zero, what is the electric potential at the point P on the y axis at y= 12 cm?
(A)5.4 V
(B)7.2 V
(C)9.0 V
(D)12.2 V
(E)16.0 V