This key facts covers Key Facts Summary within Resistance & Ohm's Law for GCSE Physics. Revise Resistance & Ohm's Law in Electricity for GCSE Physics with 16 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 9 of 16 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
📋 Key Facts Summary
- Ohm's Law: V = IR
- Resistance unit: ohms (Ω)
- Longer wire → more resistance
- Thicker wire → less resistance
- Hotter metal → more resistance (more ionic vibration)
- Hotter thermistor → less resistance
- Brighter LDR → less resistance
- Filament lamp: resistance increases as it heats up → curved V-I graph
- Diode: allows current in ONE direction only
Practice questions for Resistance & Ohm's Law
Which of the following best describes electrical resistance?
Explain what is meant by an ohmic conductor.
Quick recall flashcards
Ohm's Law equation?
V = IR where V = voltage (V), I = current (A), R = resistance (Ω)
Unit of resistance?
Ohm (Ω)