ElectricityDeep Dive

Kilowatt-Hours (kWh) — The Billing Unit

Part of Electrical Power & Energy · GCSE GCSE Physics revision

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 topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. 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!

Energy (kWh) = Power (kW) × time (hours)
Cost = Energy (kWh) × price per kWh

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

Keep building this topic

Read this section alongside the surrounding pages in Electrical Power & Energy. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Electrical Power & Energy

What is the unit of electrical power?

  • A. Joule (J)
  • B. Ampere (A)
  • C. Watt (W)
  • D. Volt (V)
1 markfoundation

Explain why the National Grid transmits electricity at high voltage to reduce energy losses.

2 marksstandard

Quick Recall Flashcards

Unit of power?
Watt (W) or joules per second (J/s)
What is 1 watt?
1 joule of energy transferred per second (1 W = 1 J/s)

15 questions on Electrical Power & Energy — practise free

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