Basics of electricity
Electrical circuit
Section titled “Electrical circuit”- An electrical circuit is an energy delivery system.
- It takes energy from the cell/battery and ‘drops it off’ at the components (such as the bulb).
Summary of the 4 main quantities
Section titled “Summary of the 4 main quantities”These are explained much more over the next few pages, but here is a summary:
| Quantity | Symbol | Unit | Unit Symbol | Definition |
|---|---|---|---|---|
| Charge | Coulomb | (no simple definition) - 1C = $6.25\times10^{18} electrons | ||
| Current | Ampere | Rate of flow of charge | ||
| Potential difference | Volt | Work done per coulomb charge | ||
| Resistance | Ohm | Opposition to current flow, ratio of p.d. to current |