# A steady current flows in a metallic conductor of the non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are (1) current, electric field and drift speed (2) drift speed only (3) current and drift speed (4) current only

When a steady current flows in a metallic conductor of non-uniform cross-section, the current flowing through the conductor is constant.  Current does not depend on the area of the conductor, hence it remains a constant. Current density, electric field, and drift speed are inversely proportional to the area of cross-section.

We can use the following formula in order to calculate drift velocity

=nAvQ

Where,

• I is the current flowing through the conductor which is measured in amperes
• n is the number of electrons
• A is the area of the cross-section of the conductor which is measured in m2
• v is the drift velocity of the electrons
• Q is the charge of an electron which is measured in Coulombs

When study or constant current flow in a metallic conductor of non-uniform cross-section then draft speed is

v = I/nAQ

v  α I/A

As a result, with non-uniform cross-sections, drift speed will vary at different places. Only the current will remain the same.