Question

:30 Φ Figure 22-53 shows two concentric rings, of radii R and R'3.00R, that lie on the same plane. Point P lies on the central z axis, at distance D-2.00R from the center of the rings. The smaller ring has uniformly distributed charge +Q. In terms of Q, what is the uni formly distributed charge on the larger ring if the net electric field at P is zero? R'

Find the ratio of Q/q for the E-field to be zero at a distance of z = 3.62R for the charge distribution and geometry of problem 22.30 of the text.

Can anyone make any sense of this? I am at a loss.

Answer 1

Let q be the charge on larger Ring Electric Field are to smaller ring E_1 = 1/4 pi epsilon_0 times theta/(AP)^2 E_1 = k theta/SR^2 Electric Field are to Larger ring E_2 = 1 q/4 pi epsilon_0(BP)^2 E_2 = k q/13R^2 at P E_p = 0 E_1 = E_2 k theta/5R^2 - k q/13R^2 q = 13 theta/5 = 2.6 theta coulumb