Understanding Kirchhoff’s Voltage Law: A Simple Guide

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
Concept | Meaning |
Voltage | Electrical energy (push) |
Voltage Rise | Energy provided (like battery) |
Voltage Drop | Energy used (like bulbs, resistors) |
Closed Loop | Complete circuit path |
KVL Rule | Supply = 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. 🙌