Physics A-Level
Ohm’s law
What Ohm’s law means in Physics A-Level, as defined for OCR.
Definitions of Ohm’s law
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain Ohm’s law in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: OCR
The current through a metallic conductor is directly proportional to the potential difference across it, provided physical conditions such as temperature remain constant.
Use V = IR to find currents and voltages.
Topics that use Ohm’s law
- Resistance (OCR A-Level)
- Series and parallel circuits (OCR A-Level)
Related terms
- Circuit analysis
- Circuit design for measurement
- Component protection
- Conservation of charge
- Conservation of energy
- Conservation of energy in electrical circuits
- Current–voltage characteristics
- Data logging and graphing
Using Ohm’s law in the exam
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