When the motor below is connected to the battery, the iron bar and copper coil spin in a circle. If no energy is lost as heat and no electrical energy remains after it runs through the coil, how much of the electrical energy flowing through the copper wire is transformed into mechanical energy?
A.
all of it
B.
half of it
C.
none of it
D.
a tiny fraction of it

Intro: a solid ball of radius rb has a uniform charge density ρ. part a: what is the magnitude of the electric field e(r) at a distance r> rb from the center of the ball? express your answer in terms of ρ, rb, r, and ϵ0. part b: what is the magnitude of the electric field e(r) at a distance r express your answer in terms of ρ, rb, r, and ϵ0. part c: let e(r) represent the electric field due to the charged ball throughout all of space. which of the following statements about the electric field are true? check all that apply. e(0) = 0 e(rb)=0 limr→∞e(r)=0 the maximum electric field occurs when r=0 the maximum electric field occurs when r=rb the maximum electric field occurs as r→∞.