• Third Preparatory, Science, Term 1 (English edition).
• The unit has three lessons (1) Electric Current, (2) Electric Circuits, (3) Electric and Magnetic Forces.
• In Lesson 1 you learn what current, potential difference, emf and resistance mean and how to measure them.
• In Lesson 2 you learn Ohm’s law, how resistors are connected, and how to calculate electric power, energy and the cost of electricity.
• In Lesson 3 you discover that electricity and magnetism are linked, which leads to the electromagnet, the electric motor and the electric generator.

🌳 Concept tree

Unit 2 — Electricity and Magnetism

│ ├── 1.1 Free electrons and electric current

│ ├── 1.2 Electric current intensity

1. │ ├── 1.3 Electric potential difference (voltage)
2. │ ├── 1.4 Electric sources and electromotive force

│ ├── 1.5 Connecting electric cells

│ ├── 1.6 Electric resistance

│ ├── 1.7 Circuit symbols and circuit diagrams

│ └── 1.8 Summary of Lesson 1

• ├── Lesson 2 Electric Circuits
• │ ├── 2.1 How is the current in a conductor determined? Ohm's law

│ ├── 2.2 Connecting identical resistors

│ ├── 2.3 Electric power and energy

│ ├── 2.4 Electrical safety

│ └── 2.5 Summary of Lesson 2

├── 3.1 The magnetic effect of electric current

├── 3.2 The electromagnet

• ├── 3.3 Magnetic force on a current-carrying wire

├── 3.4 The simple electric motor (DC motor)

├── 3.5 The electric generator

└── 3.6 Summary of Lesson 3