Understanding Kirchhoff’s Voltage Law: A Simple Guide

Ravikirana BRavikirana B
2 min read

Kirchhoff’s Voltage Law (KVL) is a fundamental principle in electronics. It helps us understand how voltage (electrical energy) is distributed in a closed circuit. Many people find this concept abstract, but it's actually very logical — especially when seen through a real-world example with bulbs and batteries.


📜 What is Kirchhoff’s Voltage Law?

KVL states:
In any closed loop of an electrical circuit, the sum of all voltages is zero.

In other words:

The total energy supplied = total energy consumed

This is based on the law of conservation of energy — energy doesn't vanish or get stored permanently in the loop. It's fully used by the components.


💡 Real-Life Example: Battery and Bulbs

Let’s say you have a 9V battery connected to two bulbs in series:

  • 🔋 Battery = 9V supply

  • 💡 Bulb A uses 4V

  • 💡 Bulb B uses 5V

  • The circuit is closed (forms a complete loop)

When current flows, the battery pushes electrons through the circuit, and each component uses some voltage.


✅ KVL in Action

Apply Kirchhoff’s Voltage Law:

+9V (battery)
-4V (Bulb A)
-5V (Bulb B)

🧮 KVL Equation:

+9 - 4 - 5 = 0

🎯 The energy supplied by the battery is exactly used up by the two bulbs.


🔁 What If One Bulb Uses Less?

Let’s say:

  • Bulb A uses 3V

  • Bulb B uses 6V

Then:

+9 - 3 - 6 = 0

Still balanced!


⚙️ Why KVL Is Useful

Kirchhoff’s Voltage Law helps us:

  • ✅ Analyze voltage drops across components

  • ✅ Design proper resistor values in a loop

  • ✅ Troubleshoot faulty circuits (if drop ≠ supply, something is wrong!)

It’s used in:

  • Power supply design

  • Sensor systems

  • LED strip configurations

  • Battery monitoring systems


🧠 Key Concepts to Remember

ConceptMeaning
VoltageElectrical energy (push)
Voltage RiseEnergy provided (like battery)
Voltage DropEnergy used (like bulbs, resistors)
Closed LoopComplete circuit path
KVL RuleSupply = All drops → Sum = 0

📘 Summary

In any closed electrical loop:
What the battery gives, all components together must use.
Nothing is wasted. Nothing is stored.

That’s Kirchhoff’s Voltage Law — clean, logical, and essential to electronics!

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Written by

Ravikirana B
Ravikirana B

I’m Ravikirana B – an engineer driven by curiosity and clarity. I specialize in electronics, Python programming, and work across a range of technologies to build real-world solutions that blend hardware and software. I started Tech Shodhaka to share what I learn, simplify what I know, and spark curiosity in those who want to understand how tech actually works — especially in our own languages and ways of thinking. Here, you’ll find: 🔧 Electronics concepts explained with analogies (like water flow, gates, tanks) 🐍 Python-based tech insights and automation ideas ⚡ Real tech reflections from both theory and hands-on work 🌿 A touch of Kannada-English expression for wider reach I believe in making learning accessible, especially for students and self-learners from smaller towns like mine. If you’re someone who loves understanding “why” and “how”, Tech Shodhaka is for you. Let’s keep exploring, clearly and curiously. 🙌