Physics A-Level
Physics A-Level glossary
10 key terms for Physics A-Level, A to Z, each linked to the topic pages that use it.
C
- Conventional Current
- The model of charge flow from the positive terminal to the negative terminal of a power supply.Pearson Edexcel
D
- Direct Current (d.c.)
- An electric current that flows in one direction only.Pearson Edexcel
E
- Electromotive Force (e.m.f.)
- The electrical energy transferred by a power supply per unit charge passing through it.Pearson Edexcel
I
- Internal Resistance
- The resistance inherent in the source itself (e.g., the battery), which causes energy to be dissipated as heat within the source.Pearson Edexcel
O
- Ohm's Law
- The current through a conductor is directly proportional to the potential difference across it, provided the temperature remains constant.Pearson Edexcel
- Ohmic Conductor
- A conductor for which current is directly proportional to potential difference, provided the temperature remains constant.Pearson Edexcel
P
- Potential Difference
- The work done (or energy transferred) per unit of charge that passes between two points.Pearson Edexcel
R
- Resistance
- The ratio of potential difference across a component to the current flowing through it (R = V/I).Pearson Edexcel
- Resistivity
- A fundamental property of a material that measures how strongly it resists electric current, independent of its dimensions.Pearson Edexcel
T
- Thermistor
- A resistor whose resistance decreases as temperature increases.Pearson Edexcel
Where these terms come from
Each definition is one we publish on a Physics A-Level topic page or study guide. Open a term to see how each exam board words it and which topic it belongs to. For the full course, go to Physics revision or the glossary for every subject.
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