In the Figure, a Ring 0

Multiple Choice

In the figure, a ring 0.71 m in radius carries a charge of + 580 nC uniformly distributed over it. A point charge Q is placed at the center of the ring. The electric field is equal to zero at field point P, which is on the axis of the ring, and 0.73 m from its center. (ε₀ = 8.85 × 10^-12 C²/N ∙ m²) The point charge Q is closest to

A) -210
B) -300
C) -420
D) 210
E) 300