Voltage vs Current Graph Builder

Reading a V-I Graph

A Voltage-Current (V-I) graph is the easiest way to visualize how an electrical component behaves. The X-axis represents the "push" (Voltage), and the Y-axis represents the actual flow of electricity (Current).

• Ohmic Materials (Straight Lines): Standard resistors follow Ohm's Law ($V = I \times R$) perfectly. Because resistance is constant, the relationship between voltage and current is strictly linear, resulting in a straight line passing through the origin (0,0).
• The Slope = Conductance: On a V-I graph, a steeper line means more current flows for a given voltage. Therefore, a steep slope indicates low resistance (high conductance), while a flat slope indicates high resistance. Mathematically, the slope equals $1 / R$.
• Non-Ohmic Materials (Curves): A filament lamp is "non-ohmic." As you push more current through the tiny wire filament, it gets extremely hot (which creates light). However, metal naturally increases in resistance as it heats up. This rising resistance causes the V-I graph to curve and flatten out at higher voltages.