Higher Tier Only: Power Loss in Transmission
Part of Electrical Power & Energy — GCSE Physics
This higher tier covers Higher Tier Only: Power Loss in Transmission 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 12 of 15 in this topic. This section is most useful once the core foundation idea is secure, because it adds the detail that pushes answers higher.
Topic position
Section 12 of 15
Practice
15 questions
Recall
30 flashcards
🎓 Higher Tier Only: Power Loss in Transmission
The National Grid transmits electricity over long distances. Power is lost as heat in the cables because cables have resistance. The power lost is given by:
To minimise loss, the current must be kept as small as possible. Since P = IV, for a given power output, a smaller current requires a higher voltage. This is why the National Grid transmits at up to 400,000 V — it reduces current, which dramatically reduces the I²R heating loss. Transformers are used to step voltage up at the power station and step it back down to 230 V for safe domestic use.