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Basic Circuit Analysis
Parallel Circuits
Section 2-4 Power in Parallel Circuits
| Definition Kirchhoff's Current Law The algebraic sum of all currents entering and leaving a node in a circuit is equal to zero. | This figure shows current I1 entering a node, and currents I2 and I3 leaving it. If I2 = 2A and I3 = 1A, Kirchhoff's Current Law (and common sense) dictates that the current entering the node is 2A + 1A, or 3A. 
|  | Examples 1. Complete this current node:  | +2 + 6 + Ik = 0 Ik = -6 | Ans: 6A leaving 2. 25mA and 40mA are entering a 3-branch node. What is the amount and direction of the third current? Ans: 65mA leaving the node. 3. Complete this current node:  | +20 + 15 - 5 + Ik = 0 Ik = -30 Ans: 30ma leaving |
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