Question

A steady-state current flows through the Nichrome wire in the circuit shown in Figure 18.90. Before attempting to answer the following questions, draw a copy of this diagram. All of the locations indicated by letters are inside the wire.

(a)On your diagram, show the electric field at the locations indicated, paying attention to relative magnitude.

(b)Carefully draw pluses and minuses on your diagram to show the approximate surface charge distribution that produces the electric field you drew. Make your drawing show clearly the differences between regions of high surface charge density and regions of low surface-charge density. Use your diagram to determine which of the following statements about this circuit are true.

(1) There is some excess negative charge on the surface of the wire near location B.

(2) Inside the metal wire the magnitude of the electric field is zero.

(3) The magnitude of the electric field is the same at locations Gand C.

(4) The electric field points to the left at location G.

(5) There is no excess charge on the surface of the wire.

(6) There is excess charge on the surface of the wire near the batteries but nowhere else.

(7) The magnitude of the electric field inside the wire is larger at location Gthan at location C.

(8) The electric field at location Dpoints to the left.

(9) Because the current is not changing, the circuit is in static equilibrium.

Short answer

(a) The direction of electric field in the circuit is as follows:

Step-by-step solution

Given data

A steady-state current flows through the Nichrome wire in the circuit.

The following statements are provided:

(1) There is some excess negative charge on the surface of the wire near location B.

(2) Inside the metal wire the magnitude of the electric field is zero.

(3) The magnitude of the electric field is the same at locations Gand C.

(4) The electric field points to the left at location G.

(5) There is no excess charge on the surface of the wire.

(6) There is excess charge on the surface of the wire near the batteries but nowhere else.

(7) The magnitude of the electric field inside the wire is larger at location Gthan at location C.

(8) The electric field at location Dpoints to the left.

(9) Because the current is not changing, the circuit is in static equilibrium.

Electric field direction

Electric field always points from the positive terminal to the negative terminal of a battery.

(a) Determination of electric field in the circuit

At steady state, the electric field is uniform everywhere and is directed from the positive to the negative terminal. This is depicted in the following diagram: