Which of the following statements are true? check all that apply. 1. in a circuit, current is delivered by the positive terminal of a battery, and it is used up by the time it returns to the negative terminal of the battery. 2. when an electric field is applied to a conductor, the free electrons move only in the direction opposite the applied electric field. 3. by convention, the direction of a current is taken to be the direction of flow for negative charges. 4. in order to maintain a steady flow of current in a conductor, a steady force must be maintained on the mobile charges. 5. current is the total amount of charge that passes through a conductor's full cross section at any point per unit of time. i've been reading this chapter in my book over and over and i still can't figure this out.

To understand the behavior of the electric field at the surface of a conductor, and its relationship to surface charge on the conductor. a conductor is placed in an external electrostatic field. the external field is uniform before the conductor is placed within it. the conductor is completely isolated from any source of current or charge. part a: which of the following describes the electric field inside this conductor? it is in the same direction as the original external field.it is in the opposite direction from that of the original external field.it has a direction determined entirely by the charge on its surface.it is always zero. part b: the charge density inside the conductor is: 0non-zero; but uniformnon-zero; non-uniforminfinite part c: assume that at some point just outside the surface of the conductor, the electric field has magnitude e and is directed toward the surface of the conductor. what is the charge density η on the surface of the conductor at that point? express your answer in terms of e and ϵ0