V=IR

• The equation V = IR stands for potential difference equals current times resistance.
• As long as the resistance stays constant, an increase in voltage should proportionally increase the current.
• If the circuit contains only wires or resistors, the lines will be straight because the resistance stays constant the entire time.
• If the circuit contains different wires or different resistors, the line will still be straight but it will be more or less steep, with a bigger resistor having a less steep line and a smaller resistor having a steeper line.
• If the circuit contains a filament lamp, which is just a light bulb with a very thin metal filament, the curve gets less steep as the current increases because the wire heats up and its resistance increases.
• Diodes are devices that only allow current to flow in one direction, so they only show a current when the potential difference is positive, doing this by having a really high resistance in the reverse direction.