ElectricityTopic Summary
Topic Summary: Electrical Power and Energy
Part of Electrical Power & Energy — GCSE Physics
This topic summary covers Topic Summary: Electrical Power and Energy within Electrical Power & Energy for GCSE Physics. Revise Electrical Power & Energy in Electricity for GCSE Physics with 15 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 15 of 15 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 15 of 15
Practice
15 questions
Recall
30 flashcards
Topic Summary: Electrical Power and Energy
Key Terms
- Power (P): Rate of energy transfer (W)
- Watt: 1 joule per second
- kWh: Billing unit (1 kW for 1 hour)
- Energy: Power × time (J or kWh)
Key Facts
- 1 kW = 1000 W
- 1 kWh = 3,600,000 J
- High current = high power loss (I²R)
- Cost = kWh × price per unit
Key Equations
- P = IV
- P = I²R
- P = V²/R
- E = Pt (joules, seconds)
- E = P(kW) × t(h) (kWh)
Exam Tips
- Match equation to given quantities
- kWh needs kW and hours (not seconds)
- Always state units: W, J, or kWh
- Cost = kWh × unit price