A steady current is passing through a linear conductor of non‑uniform cross section. The net quantity of charge crossing any cross section per second is:

Steady Current in Non‑Uniform Conductor – Charge Flow

Question: A steady current is passing through a linear conductor of non‑uniform cross section. The net quantity of charge crossing any cross section per second is:

a) independent of the area of cross section

b) directly proportional to area of cross section

c) directly proportional to length of cross section

d) inversely proportional to length of cross section

Detailed Solution:

By definition, electric current I is the rate of flow of charge through any cross section:

\[ I = \frac{\mathrm{d}Q}{\mathrm{d}t} \]

In a steady (steady-state) current, the same amount of charge per unit time must pass through every cross section of the conductor, regardless of its area or shape. This ensures charge conservation (continuity equation) in the circuit.

Therefore, the net charge crossing each section per second—i.e., the current—is independent of the cross-sectional area.

Correct answer: (a) independent of the area of cross section