Kirchhoff's Current Law describes what at a junction?

• A. Voltage conservation
• B. Current conservation
• C. Power conservation
• D. Charge conservation

Answer: (B)

Kirchhoff's Current Law is about what happens to current at a junction. It says the total current flowing into a node must equal the total current flowing out, so the algebraic sum of currents at the node is zero. This reflects current conservation: in the lumped-parameter circuit model, charge cannot accumulate at a point, so whatever comes in must go out (aside from tiny parasitic storage). In practice, you assign a sign convention and add all currents at the node; the sum should be zero for a valid circuit.

This is why current conservation is the correct description for a junction. Other ideas refer to different aspects of circuit behavior: voltage is governed by how potentials relate around a loop (Kirchhoff’s Voltage Law), power conservation is an energy balance (P = VI) rather than a local node rule, and charge conservation underpins these laws, but KCL specifically describes the balance of currents at a node.