Question

A constant current $I$ is flowing along the length of a conductor of variable cross-section as shown in the figure. The quantity which does not depend upon the area of cross-section is

• A. electron density
• B. current density
• C. drift velocity
• D. electric field

Answer 1

Answer: (A)

When a constant current is flowing through a conductor of non-uniform cross-section, electron density does not depend upon the area of cross section, while current density, drift velocity and electric field all vary inversely with area of cross-section