By Timothy Burns Updated Mar 24, 2022
Ohm's Law defines the relationship between voltage, current (amperage), and resistance in an electrical circuit. These three properties are interdependent; changing one instantly affects the other two. Voltage (V) is the product of current (I) and resistance (R). The law is expressed by the equation V = I × R. Therefore, to increase the current in a circuit, you can either lower the resistance or raise the voltage, keeping the other variable constant.
When the supply voltage is held steady, the current rises as the resistance falls. In practice, this means using conductors with a larger cross‑sectional area—i.e., thicker copper or aluminum wires—because resistance is inversely proportional to wire diameter. Upgrading to a higher‑grade conductor will therefore boost current flow without altering the source voltage.
If the circuit contains discrete resistors, replacing a high‑value resistor with a lower one directly reduces total resistance. For example, substituting a 4 Ω resistor with a 2 Ω part halves the resistance. With the supply voltage unchanged, this change will double the current through the circuit, as per Ohm's Law.
When resistance cannot be changed, the only way to raise current is to increase the applied voltage. Think of the circuit as a water pipe: voltage is the water pressure, resistance is the pipe’s diameter, and current is the flow rate. If you double the pressure while keeping the pipe size constant, the flow rate also doubles.
Always observe safety protocols when working with live circuits, and verify component ratings before making changes.
