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Ohm's Law - A Level Physics Definition

Reviewed by: Leander Oates

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What is Ohm's Law?

In A Level Physics, Ohm's Law states that for a conductor at a constant temperature, the current through it is directly proportional to the potential difference across it.

The equation for Ohm's law is:

V space equals space I R

Where:

  • V = potential difference, measured in volts (straight V)

  • I = current, measured in amps (straight A)

  • R = resistance, measured in ohms (straight capital omega)

Ohm's Law applies only to ohmic conductors, where the resistance remains constant regardless of the voltage and current.

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Leander Oates

Reviewer: Leander Oates

Expertise: Senior Physics Content Creator

Leander graduated with First-class honours in Science and Education from Sheffield Hallam University. She won the prestigious Lord Robert Winston Solomon Lipson Prize in recognition of her dedication to science and teaching excellence. After teaching and tutoring both science and maths students, Leander now brings this passion for helping young people reach their potential to her work at SME.

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