This definitions covers Key Definitions within Resistance & Ohm's Law for GCSE Physics. Revise Resistance & Ohm's Law in Electricity for GCSE Physics with 14 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 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
14 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.