Three Power Equations — When to Use Each
Part of Electrical Power & Energy · GCSE GCSE Physics revision
This deep dive covers Three Power Equations — When to Use Each 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 2 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 2 of 15
Practice
15 questions
Recall
30 flashcards
📚 Three Power Equations — When to Use Each
P = IV — Use when you know current AND voltage
P = I²R — Use when you know current AND resistance (no voltage given)
P = V²/R — Use when you know voltage AND resistance (no current given)
How these all connect (combining P = IV with V = IR):
- P = IV, substitute V = IR → P = I × (IR) = I²R
- P = IV, substitute I = V/R → P = (V/R) × V = V²/R
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?
Explain why the National Grid transmits electricity at high voltage to reduce energy losses.
Quick Recall Flashcards
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