This definitions covers Key Definitions 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 8 of 16 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 8 of 16
Practice
16 questions
Recall
30 flashcards
📖 Key Definitions
Resistance (R): A measure of how much a component opposes the flow of electric current. Measured in ohms (Ω). Formula: R = V/I.
Ohm (Ω): The SI unit of resistance. 1 Ω = 1 V/A (one volt per amp).
Ohm's Law: The potential difference across a conductor is directly proportional to the current through it, provided temperature remains constant. V = IR.
Ohmic conductor: A component whose resistance stays constant regardless of current (e.g., fixed resistor at constant temperature). Gives a straight-line V-I graph through the origin.
Thermistor: A component whose resistance decreases as temperature increases. Used as a temperature sensor.
LDR (Light-Dependent Resistor): A component whose resistance decreases as light intensity increases. Used as a light sensor.
Keep building this topic
Read this section alongside the surrounding pages in Resistance & Ohm's Law. That gives you the full topic sequence instead of a single isolated revision point.
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
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