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A student writes a node equation as $I_1+I_2=I_3-I_4$. Which correction best reflects standard Kirchhoff's Current Law usage?
ACurrents on one side of the equation should represent entering currents and the other side leaving currents, with signs assigned consistently.
BSubtraction is never allowed in current equations.
CKirchhoff's Current Law can only be used when exactly four branches meet.
DThe equation should involve voltages instead of currents.
Answer & Solution
Correct answer: A. Currents on one side of the equation should represent entering currents and the other side leaving currents, with signs assigned consistently.
KCL can be written in many algebraically equivalent forms, including with subtraction, but the signs must consistently reflect current directions. A standard form is: sum of entering currents equals sum of leaving currents, or equivalently the algebraic sum of currents at a node is zero.