The diagram shown represents a portion of a wire in a circuit. A current is flowing in the wire in the direction shown. Under the convention that it is positive charge that flows the electric field points in the direction of the current. How can the electric field change direction where the wire bends?
A)There is an excess of negative charge in the center of the wire.
B)There is an excess of positive charge at the bottom end of the wire.
C)There is an excess of negative charge at the right end of the upper portion of the wire.
D)There is an accumulation of positive charge on the surface, particularly at the bend, such that the sum of electric fields gives the new electric field.
E)There is an accumulation of electrical potential as the current traverses the wire: The higher potential in the lower half is the source of the field.

Question

The diagram shown represents a portion of a wire in a circuit. A current is flowing in the wire in the direction shown. Under the convention that it is positive charge that flows the electric field points in the direction of the current. How can the electric field change direction where the wire bends? 
A)There is an excess of negative charge in the center of the wire. 
B)There is an excess of positive charge at the bottom end of the wire. 
C)There is an excess of negative charge at the right end of the upper portion of the wire. 
D)There is an accumulation of positive charge on the surface, particularly at the bend, such that the sum of electric fields gives the new electric field. 
E)There is an accumulation of electrical potential as the current traverses the wire: The higher potential in the lower half is the source of the field.

Quizplus · Accepted Answer

When the wire bends, there is a buildup of positive charge on the surface of the wire, particularly at the bend. This accumulation of charge results in an electric field that points towards the inside of the bend, which is perpendicular to the original direction of the field. The sum of these two fields gives the new electric field, which changes direction at the bend.

The Diagram Shown Represents a Portion of a Wire in a Circuit