Kirchhoff’s Voltage Law (KVL) is a fundamental principle in circuit analysis based on the Law of Conservation of Energy. KVL states that the algebraic sum of all voltages around any closed loop in a circuit is equal to zero.
Table of Contents
Mathematical Expression
\sum V = 0
Concept
In simple terms: Energy Supplied = Energy Consumed
As an electric charge moves around a closed loop:
- It gains energy from sources (like batteries)
- It loses energy across elements (like resistors)
Since the charge returns to its starting point, the net energy change is zero.
How to Apply KVL
Follow these steps to apply KVL in circuit analysis:
Step 1: Define a Loop
Choose any closed path in the circuit.
Step 2: Assign Direction
Select a direction to traverse the loop:
- Clockwise or
- Counter-clockwise
Step 3: Apply Sign Convention
- Voltage Drop: Moving from (+) to (–) → Negative
[
-IR
] - Voltage Rise: Moving from (–) to (+) → Positive
[
+V
]
Step 4: Apply KVL Equation
Add all voltages in the loop and equate to zero, then solve.