Question

The sphere of a Van de Graaff generator has a charge of +3.28 μC. A small metal sphere nearby has a charge of +219 nC. They are separated 2.00 m. Let us set axes so that the origin is at the centre of the Van de Graaff generator and the small sphere is at 2.00ˆi m. They are far enough apart that we can make the approximation that they are not polarizing each other, so they can be treated as uniformly charged spheres.

(a) Find the electric field (vector) at each of the positions:

• Point A: 1.50ˆi m

• Point B: 1.50ˆi − 0.50ˆj m

(b) Use your result from part a) to determine the acceleration (vector) of an electron passing through point B.

(c) Write the function Ey(y), for points on the line x = 1.50 m. Use a spreadsheet to graph this function. Let the horizontal scale of your graph extend from y = −10 m to y = 10 m.

(d) According to your graph (or just looking at the form of the function), where is Ey = 0 along the x = 1.50 m line? Is E⃗ = 0 at this same point? Explain ?

Answer 1