Final answer:
Ohm's law states that voltage drop across a resistor is calculated using V = IR, where V is voltage, I is current, and R is resistance.
Step-by-step explanation:
According to Ohm's law, the voltage drop, V, across a resistor, when a current flows through it is calculated using the equation V = IR, where I equals the current in amps (A) and R is the resistance in ohms (Ω). Another way to think of this is that V is the voltage necessary to make a current I flow through a resistance R. Ohm's Law essentially states that the voltage across a resistor is directly proportional to the current flowing through it, with the resistance acting as a constant of proportionality. This law applies to various components in an electrical circuit, including resistors, conductors, and other devices that follow Ohmic behavior.