Kirchhoff’s voltage law or KVL formula relates the behavior of voltage in a loop. A loop is a circular path formed by the combination of resistors.
Statement: The sum of voltage rise in a closed loop is equal to the sum of voltage drop in that loop. The mathematical equation which relates the KVL:
Let’s consider the closed loop circuit with three resistors and a voltage source.
Example: A 5 V input source powers three series resistors. The voltage drop across first and third resistors is 2 volts respectively. Find the voltage across the second resistor.
∑Voltagerise = ∑Voltagedrop
Vin = V1 + V2 + V3
5 V = 2 V + V2 + 2 V
V2 = 5 V – 2 V – 2 V
V2 = 1 V