Potential Difference
Also known as: voltage drop, pd
The difference in electric potential between two points, equal to the work done per unit charge moving between them. Links the abstract concept of electric field to the practical concept of voltage used in circuits and power systems.
💡 Intuition
Potential difference is the 'height drop' that makes charges flow — the bigger the drop, the harder the push.
Core Idea
Potential difference is what actually drives current in circuits — it's the 'voltage' engineers measure.
Formal View
🔬 Example
🎯 Why It Matters
Links the abstract concept of electric field to the practical concept of voltage used in circuits and power systems.
⚠️ Common Confusion
Voltage is always measured between two points — saying 'the voltage at this wire' implicitly means relative to ground.
💭 Hint When Stuck
When solving a potential difference problem, identify the two points you are comparing. First, find the electric potential at each point (or the work done moving a charge between them). Then subtract: \Delta V = V_B - V_A. Finally, use \Delta V = W/q to relate voltage to energy and charge.
Related Concepts
Prerequisites
How Potential Difference Connects to Other Ideas
To understand potential difference, you should first be comfortable with electric potential and voltage.
Go Deeper
Frequently Asked Questions
What is Potential Difference in Physics?
The difference in electric potential between two points, equal to the work done per unit charge moving between them.
Why is Potential Difference important?
Links the abstract concept of electric field to the practical concept of voltage used in circuits and power systems.
What do students usually get wrong about Potential Difference?
Voltage is always measured between two points — saying 'the voltage at this wire' implicitly means relative to ground.
What should I learn before Potential Difference?
Before studying Potential Difference, you should understand: electric potential, voltage.