Circuit
Also known as: electric circuit, closed circuit
A closed loop of conducting material through which electric current can flow, typically including a power source and one or more components. Every electrical device depends on circuits, from the simplest flashlight to the most complex computer.
💡 Intuition
A circuit is a complete loop — like a circular track that electrons run around. Break the loop and everything stops.
Core Idea
Current only flows when the circuit is complete — a break anywhere stops the entire flow.
Formal View
🔬 Example
🎯 Why It Matters
Every electrical device depends on circuits, from the simplest flashlight to the most complex computer.
⚠️ Common Confusion
A switch works by physically breaking the circuit (open = off, closed = on).
💭 Hint When Stuck
When analysing a circuit, first trace the path from the positive terminal of the power source through each component and back to the negative terminal. Check whether the loop is complete — if there is any break, no current flows. Then identify whether components are in series (one path) or parallel (branching paths).
Related Concepts
Prerequisites
How Circuit Connects to Other Ideas
To understand circuit, you should first be comfortable with electric current and voltage. Once you have a solid grasp of circuit, you can move on to series circuit, parallel circuit and circuit diagram.
Go Deeper
Frequently Asked Questions
What is Circuit in Physics?
A closed loop of conducting material through which electric current can flow, typically including a power source and one or more components.
Why is Circuit important?
Every electrical device depends on circuits, from the simplest flashlight to the most complex computer.
What do students usually get wrong about Circuit?
A switch works by physically breaking the circuit (open = off, closed = on).
What should I learn before Circuit?
Before studying Circuit, you should understand: electric current, voltage.