Electromagnetism & Basic Electronics

What this lesson covers

Electromagnetism & Basic Electronics is a 8-part Class 10 Physics lesson. Each part makes one point and then hands over to the next, so it can be read in a sitting or picked up again at the part you stopped on. It defines the idea in plain words before using it, works through an example step by step, breaks the topic into its parts and compares them, shows where it is used outside the textbook, names the mistakes that cost marks in an exam, ends with a recap of what to remember.

How it begins

A current-carrying wire produces a magnetic field around it in concentric circles. That single fact (discovered by Ørsted when a compass needle twitched near a wire) connects electricity and magnetism permanently. Coil the wire into a solenoid and the fields add, producing a field like a bar magnet's. Add an iron core and it becomes an electromagnet, whose great advantage is that it can be switched off.

The 8 parts

1. Magnetism from current
2. The motor effect
3. Induction and transformers
4. A transformer calculation
5. The grid, and everything with a motor
6. Where marks get lost
7. What to remember
8. Watch one worked through