The figure on the left shows a positively charged plastic rod of length L = 0.80
ID: 1330388 • Letter: T
Question
The figure on the left shows a positively charged plastic rod of length L = 0.80 m and uniform linear charge density 8.00×10-3 C/m. Setting V= 0 at infinity and considering Fig. 25-13 and Eq 25-35, find the electric potential at point P for d = 0.464 m.
The figure on the right shows an identical rod, except that it is split in half and the right half is negatively charged; the left and right halves have the same magnitude ? of uniform linear charge density, what is the electric potential at point P in the figure?
L/2Explanation / Answer
For figure a) positively charge rod electric potential along the axis that passes through the midpoint of a non-conducting rod,
V= (/20)ln(L/d) = (8*10^-3/(2*3.14*8.85*10^-12))ln(0.8/0.464) = 7.84*10^7 V
For figure b),
VTotal = V+ + V- = kln[((L/2)+sqrt((L/2)^2+d^2))/ d]- kln[((L/2)+sqrt((L/2)^2+d^2))/ d] = 0V