Kirchhoff's Voltage Law Calculator

| Added in Physics

What is Kirchhoff's Voltage Law and Why Should You Care?

Kirchhoff's Voltage Law (KVL) states that the sum of all the voltages around a closed loop in a circuit must equal zero. Understanding and applying KVL can save your project, whether you are a hobbyist or an electrical engineer designing complex systems.

How to Calculate Source Voltage Using KVL

The formula is straightforward:

[\text{Source Voltage} = V_1 + V_2 + V_3 + ... + V_n]

Where:

  • Source Voltage is the total voltage in the loop
  • V1, V2, Vn are the individual voltage drops or rises in the closed loop

The sum of all voltages in a closed loop equals zero when considering both sources and drops with proper sign convention.

Calculation Example

Imagine you have the following voltages in a loop:

  1. Voltage 1: 5V
  2. Voltage 2: 10V
  3. Voltage 3: -3V (negative indicates opposite polarity)
  4. Voltage 4: 8V

To find the source voltage:

[\text{Source Voltage} = 5V + 10V - 3V + 8V = 20V]

Step-by-Step Breakdown

[\begin{align*}
\text{Source Voltage} &= 5V + 10V - 3V + 8V \
&= 15V - 3V + 8V \
&= 12V + 8V \
&= 20V
\end{align*}]

So, the source voltage is 20V.

Summary Table

Voltage Value
V1 5V
V2 10V
V3 -3V
V4 8V
Total 20V

By following this simple calculation, you can analyze circuits and determine unknown voltages with confidence.

Frequently Asked Questions

Kirchhoff's Voltage Law states that the sum of all voltages around a closed loop in a circuit must equal zero. This fundamental principle helps analyze complex electrical circuits.

Yes, voltages can be negative. Use negative values for voltage drops and positive values for voltage sources, or vice versa, as long as you maintain consistent sign convention.

In a closed loop, all energy supplied by sources is consumed by components. The algebraic sum of all voltages (sources minus drops) equals zero, reflecting energy conservation.

Use KVL when analyzing circuits with multiple loops or when you need to find unknown voltages in a circuit. It is essential for solving complex circuit problems.