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## The Relationship Between Current and Potential Difference The relationship between the current through a conductor and applied potential difference was first discovered by German scientist George Simon Ohm in 1828 AD. This relationship is known as Ohm’s Law. It states that the current *I* thro...

## The Relationship Between Current and Potential Difference The relationship between the current through a conductor and applied potential difference was first discovered by German scientist George Simon Ohm in 1828 AD. This relationship is known as Ohm’s Law. It states that the current *I* through a conductor is directly proportional to the potential difference *V* applied across its two ends, provided the state of the conductor remains unchanged. The graph of current versus potential difference across the conductor is a straight line as shown in Fig. 11.4. ### I-V Curve for a Conductor The relationship between current *I* and potential difference *V* for a conductor can be described by the following equation: $I \propto V$ or $V = IR$ or $R = \frac{V}{I}$ where *R* is a proportionality constant called the resistance of the conductor. The unit of resistance is ohms (Ω). $1 \Omega = \frac{1 Volt}{1 Ampere}$ This means that if a potential difference of 1 Volt across a conductor produces a current of 1 Ampere through it, then the resistance of the conductor is 1Ω.