Why the total voltage in a closed loop always equals zero

Science · Published 28 October 2026 Swipe more like this →

In short: Understand the fundamental principle governing electrical circuits. This video explains how Kirchoff's Loop Rule applies the law of conservation of energy to calculate component voltages.

The rule dictates that the sum of all voltages throughout an entire closed loop must equal zero. This is a direct application of the law of conservation of energy, ensuring that energy gained from sources like batteries is fully accounted for as it moves through components like resistors.

While introductory physics focuses on simple circuits with one battery and resistor, the rule scales to more complex systems involving capacitors and parallel circuitry.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• Why the sum of voltages in any closed loop is always zero
• Why electricity never simply disappears at a junction
• Why electricity behaves differently when components share a single loop
• The impossible physics of a perfect voltage source
• How a simple physics experiment led to a fundamental constant of the universe
• Motion is energy, but mass determines how much of it
• The Soviet spy who built a Canadian identity from a dead man’s stolen papers
• The constant dance between motion and position
• Energy is never lost; it only changes its form
• How fast can a grasshopper jump? Use physics to calculate the acceleration yourself.
• The Sun as the ultimate architect of our global energy
• The 1968 report that diagnosed a nation's fracture

More in Physics · More in Science · Latest · A–Z · All topics