PHYSICS · Single correct · AP · Physics C: Electricity and Magnetism · Conductors and Capacitors · Conductors and Capacitors
Problem
Two identical rods, one made of plastic and the other of copper, are each given the same net positive charge. After sufficient time passes, which statement best compares the electric field at interior points well away from the surfaces of the two rods?
(a) The plastic rod has a non-zero internal electric field, whereas the copper rod’s internal electric field is zero.
(b) Both rods have zero internal electric field because any excess charge spreads out until equilibrium is reached.
(c) The plastic rod’s internal electric field is zero, whereas the copper rod has a uniform non-zero internal electric field.
(d) Both rods have the same non-zero internal electric field because they carry the same amount of excess charge.