Question

1)A ring-shaped conductor with radius a = 3.00 cm has a total positive charge Q = 0.124 nC uniformly distributed around it.(Figure 1) What is the magnitude of the electric field at point P, which is on the positive x-axis at x = 36.0 cm ?

2)A particle with a charge of − 2.10 μC is placed at the point P described in part A. What is the magnitude of the force exerted by the particle on the ring?

d0 ds dE Cl dEy 0 dE 0

Answer 1

E = K Q x / ( x^2 + a^2 )^(3/2)

E = 8.99*10^9 * 0.124*10^-9 *0.41 / ( 0.36^2 + 0.03^2)^1.5

E = 9.69 N/C



b) F = qE = 2.10*10^-6 *9.69 = 2.03*10^-5 N