9702 · 20.1
Concept of a magnetic field
Welcome to the world of **magnetic fields**, an invisible yet powerful force shaping much of our technology! In this lesson, we'll explore what these fields are, how to visualise them with **magnetic field lines**, and learn to quantify their strength using **magnetic flux density (B)**. We'll also discover how simple electric currents can generate their own fascinating magnetic effects. This pilot aligns with **Senpai Corner** A Level notes (2025–2027) for topic **20.1**.
Need to know
What you need to know
- **Direction:** Field lines point from North to South poles outside a magnet.
- **Strength:** The density of the lines (how close they are) represents the field strength. Closer lines mean a stronger field.
- **No Crossing:** Magnetic field lines never cross each other, as the field has a unique direction at any given point.
- **Continuity:** They form continuous closed loops, passing through the magnet from South to North internally to complete the circuit.
Explanation
Concept of a magnetic field
- **Direction:** Field lines point from North to South poles outside a magnet.
- **Strength:** The density of the lines (how close they are) represents the field strength. Closer lines mean a stronger field.
- **No Crossing:** Magnetic field lines never cross each other, as the field has a unique direction at any given point.
- **Continuity:** They form continuous closed loops, passing through the magnet from South to North internally to complete the circuit.