Electrical Laws
Kirchhoff’s Voltage Law (KVL)
Kirchhoff’s voltage law states that the algebraic sum of voltage changes around any closed loop is zero. In a simple series circuit this means the source voltage equals the sum of the voltage drops across the elements. The law follows from energy conservation: a charge that travels around a closed loop must return to the same potential it started from.
Kirchhoff’s Voltage Law (KVL)
Σ V = 0
Variables and units
| Symbol | Quantity | Unit |
|---|---|---|
| Σ V | Algebraic sum of voltage changes around a closed loop | V |
Conditions of application
Energy conservation around a closed loop of a lumped circuit. Choose a loop direction and keep the sign convention consistent for rises and drops.
Worked example
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