Question

What is the principle of KVL?

Answer 1

Kirchhoff’s Voltage Law (KVL) is a fundamental principle in electrical circuits. It states that:

**The sum of all voltages (potential differences) around any closed loop or mesh in a circuit is equal to zero.**

This is based on the principle of energy conservation. In simple terms, KVL says that the energy gained by charges moving through a voltage source is completely used up by the other components (like resistors, capacitors, etc.) in the loop.

### Mathematically:
If you have a closed loop in a circuit, the sum of the voltages (positive and negative) around that loop is:

\[
\sum V = 0
\]

### Why is this true?
Imagine you have a circuit with a battery and some resistors in a loop. The battery provides energy to the electrons (which is a voltage), and as the electrons move through resistors or other components, they lose energy. The total energy gained (from the battery) must be balanced by the total energy lost (in the resistors or other components).

### Example:
In a simple loop with a battery and two resistors:
- The battery provides a voltage of 10V.
- The first resistor drops 6V, and the second resistor drops 4V.

If you go around the loop, the total voltage change will be:
\[
+10V - 6V - 4V = 0V
\]

This shows that the sum of the voltage drops (and gains) in the loop is zero, as required by KVL.

In short, KVL helps us analyze complex circuits by understanding how voltage behaves in loops!