Kirchhoff’s Current Law (KCL) — the law says “the current flowing into a node equals the sum of the voltages in the output branches.” Is this statement accurate, or is it misstating KCL?

Introduction / Context:
Kirchhoff’s Current Law (KCL) is a foundational rule in circuit analysis. This question checks whether you can distinguish the correct KCL statement from a common mistake that mixes up current with voltage.

Given Data / Assumptions:

• A single node (junction) where several elements connect.
• Steady-state or time-varying currents are both allowed.
• Linear or nonlinear elements do not change KCL itself.

Concept / Approach:
KCL states: the algebraic sum of currents at a node is zero. Equivalently, the total current entering a node equals the total current leaving that node. The incorrect statement in the stem replaces “currents” with “voltages” for the outgoing branches, which is a category error because KCL is about current continuity, not voltage sums.

Step-by-Step Solution:

Verification / Alternative check:
Dimensional analysis: current has units of amperes, while voltage has volts; adding voltages to equal a current violates units. KCL is derived from charge conservation, independent of element types.

Why Other Options Are Wrong:

• Correct: Not correct because KCL never equates current to a sum of voltages.
• Only true for DC circuits: KCL applies to AC and transient circuits as well.
• Only true when all resistors are equal: Component equality is irrelevant to KCL.

Common Pitfalls:
Confusing KCL (currents at a node) with KVL (voltages around a loop); mixing variable types in verbal statements of laws.

Final Answer:
Incorrect — the statement misstates KCL, which relates currents, not voltages.