You are standing 10 meters from a light source. then, you back away from the light source until you are 20 meters away from it. from your perspective, what has happened to the intensity of the wave? a) it has decreased by a factor of two. b) it has increased by a factor of two. c) it has decreased by a factor of four. d) it has increased by a factor of four.

Athin nonconducting rod with a uniform distribution of positive charge q is bent into a circle of radius r. the central perpendicular axis through the ring is a z-axis, with the origin at the center of the ring. a) what is the magnitude of the electric field due to the rod at z = 0? n/c (b) what is the magnitude of the electric field due to the rod at z = infinity? n/c (c) in terms of r, at what positive value of z is that magnitude maximum? r (d) if r = 4.00 cm and q = 9.00 µc, what is the maximum magnitude? n/c