Practical electricity
Electrical heating, power, energy, cost, household hazards, protection and safe mains wiring.
Learning goals
- Explain electrical heating in common appliances
- Apply P = VI
- Apply E = VIt
- Calculate electrical energy and cost in kWh
- Identify the hazard from damaged insulation
- Identify the hazard from overheating cables
- Identify the hazard from damp conditions
- Explain how fuses and circuit breakers protect circuits
- Choose and justify an appropriate fuse rating
- Explain why metal casings are earthed
- Explain why double-insulated appliances do not need an earth wire
- State the meanings and roles of live, neutral and earth
- Describe the wiring of a mains plug
- Explain live-wire placement of switches, fuses and circuit breakers
G2 Science (Physics) · Topic 12
Read the complete lesson from top to bottom first. Pause for its examples and independent questions, then use a short topic check to decide what to practise again.
Before you begin
Build the idea in order
- Heating, power and energy
- Electricity cost
- Hazards and protection
- Safe mains wiring
Lessons
Practical Electricity
Electrical heating, power, energy and cost, household hazards, protection, conductor roles and safe mains-plug wiring.
Check your understanding
Practical electricity topic check
Check the required topic capabilities and get focused practice for ideas that need another look.
What to remember
- Use P = VI, E = VIt and kW × h for billing.
- Choose the smallest suitable fuse above normal current.
- Earthing supplies a low-resistance fault path.
- Live is brown, neutral blue and earth green/yellow.
- Switches and protection belong in live.
Topic and syllabus information
Practical electricity is Topic 12 in K223 / K224 Physics component · 2027.
The lesson stays within G2 depth and includes the explanations, examples and practice needed for this topic.
Reviewed 9 Aug 2026
Continue with the next resource in this course.
Course and syllabus information
- Course
- SEC G2 Science Physics component
- Edition
- SEC G2 Science Physics component 2027