Kilowatt-Hours (kWh) — The Billing Unit
Part of Electrical Power & Energy — GCSE Physics
This deep dive covers Kilowatt-Hours (kWh) — The Billing Unit 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 3 of 15 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 3 of 15
Practice
15 questions
Recall
30 flashcards
⚡ Kilowatt-Hours (kWh) — The Billing Unit
What it is: The energy used by a 1 kW appliance running for 1 hour.
Why we use it: Joules are too small for household bills. 1 kWh = 3,600,000 J!
Example calculation:
- 3 kW kettle used for 5 minutes = 3 × (5/60) = 3 × 0.083 = 0.25 kWh
- At 30p per kWh: Cost = 0.25 × 30 = 7.5p