Current, Potential Difference & Resistance

The relationship

• The current through a component depends on the resistance of the component and the potential difference across it
• The greater the resistance, the smaller the current for a given potential difference
• Recall this equation:

$$V = I R$$

• $V$ potential difference in volts, V; $I$ current in A; $R$ resistance in ohms, Ω
• Rearranged: $I = \dfrac{V}{R}$ and $R = \dfrac{V}{I}$
• Worked example: 6 V across a 30 Ω resistor gives $I = \dfrac{6}{30} = 0.2$ A
• Questions say "potential difference"; "voltage" is also credited. Potential difference is the energy transferred per coulomb of charge