What is Kirchhoff's Voltage Law (KVL)?

Kirchhoff's Voltage Law, often abbreviated as KVL, is a fundamental principle in electrical engineering and circuit analysis. It states that the algebraic sum of all electrical potential differences (voltages) around any closed circuit loop is equal to zero. In simpler terms, the energy supplied by the source in a loop must equal the energy consumed by the components within that same loop.

How to Use the KVL Calculator

This tool helps you visualize how voltage drops across resistors in a series circuit. To use the calculator, enter your source voltage (total EMF) and add the resistance values of your components. The tool will automatically calculate the total resistance, the circuit current, and the individual voltage drops across each resistor, demonstrating that the sum of these drops equals the source voltage.

Key Formula and Concepts

The mathematical representation of KVL is ΣV = 0. For a series circuit with a source voltage (Vs) and resistors (R1, R2, R3...), the steps are:

• Total Resistance (Rt): Rt = R1 + R2 + ... + Rn
• Circuit Current (I): I = Vs / Rt
• Voltage Drops (Vn): Vn = I × Rn
• Verification: Vs = V1 + V2 + ... + Vn

Frequently Asked Questions

Can KVL be applied to parallel circuits?

KVL applies to any closed loop within a circuit. In a parallel circuit, each branch forms its own loop with the source, which is why the voltage across parallel branches is always the same.

Does KVL apply to AC circuits?

Yes, KVL applies to both DC and AC circuits. In AC circuits, however, you must perform the summation using phasors to account for phase differences between voltage and current.