Ohm's Law

Ohm's Law links three quantities in a simple circuit: voltage pushes electric charge, current is the flow of charge, and resistance is how strongly the circuit opposes that flow. In many everyday materials at constant temperature, doubling the voltage produces about twice the current, while increasing resistance reduces the current, which is why the relation V = IR is so useful for linear resistive circuits.

Use this when analyzing simple DC circuits or any circuit element that behaves like a resistor, such as checking current through a component or finding the voltage drop across it. It is especially helpful in electronics, lab work, and basic circuit troubleshooting.

• Using milliamps as amps without converting first
• Rearranging the formula incorrectly when solving for I or R
• Applying Ohm's Law to non-ohmic devices without checking whether the relationship is linear