Difficulty: Easy
Correct Answer: True
Explanation:
Introduction / Context:Kirchhoff’s Current Law is one of the two foundational network laws used in circuit analysis. It enforces charge conservation at a node (junction) and underpins nodal analysis, Thevenin/Norton conversions, and network simulators.
Given Data / Assumptions:
Concept / Approach:KCL states that the algebraic sum of currents at a node equals zero, which is equivalent to “sum of currents entering equals sum of currents leaving.” This is a direct consequence of charge conservation: a node cannot store net charge over time in the lumped-parameter assumption, hence what flows in must flow out.
Step-by-Step Solution:
Choose a sign convention: currents entering positive, leaving negative.Write KCL: Σ I_k = 0 across all connected branches.Rearrange: Σ I_in = Σ I_out, which matches the statement.Apply to example node with three branches to verify numerically.Verification / Alternative check:Use nodal analysis on a simple parallel network; solving produces branch currents whose sum equals the source current, confirming KCL at the supply node.
Why Other Options Are Wrong:
Common Pitfalls:Inconsistent current directions leading to sign errors; always define arrows and stick to them to avoid apparent “violations” of KCL.
Final Answer:True
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