A current passes through a wire of non-uniform cross-section. Which of the following quantities are independent of the cross-section?

Formula used : current density is given by

current density ,

Where

i→ current

A→ area of the cross section

n→ electrons per unit area.

→ Drift speed

Current density is inversely proportional to area of the Ross section. So area of the cross section is depends on current density.

Drift speed is also inversely proportional to area of the cross section. So area of the cross section is depends drift speed.

It does not depends on free electron density and the charge crossing in a given time interval.

A current passes through a wire of non uniform cross-section. Then it does not depends on The charge crossing in a given time interval and free electron density. Option A and D are correct.