A2L Item 170
- Description: Identify electrical quantities that change depending upon conductor shape.
- Goal: Recognize macroscopic and microscopic quantities
- Source: 283 Resistance variations with area.
- Keywords: Electromagnetism, Resistance
The question for students:
An
ohmic conductor is carrying a current. The cross-sectional area of the
wire changes from one end of the wire to the other. Which of the
following quantities vary along the wire?
- The resistivity
- The current
- The current density
- The electric field
- A only
- B only
- C only
- D only
- A and B only
- C and D only
- A, B, C, and D
- None of the above
Commentary for teachers:
Answer
(6) Students are likely to appreciate that the current density varies and that the total current does not. Many will not recognize that the electric field is related to the current density.