3.6 Ohm’s Law

Ohm’s Law: Ohm’s Law is a fundamental principle in electronics and electrical engineering that describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. The law is named after German physicist Georg Simon Ohm, who first formulated it. The formula for Ohm’s Law is expressed as:

• Voltage (V): Measured in volts (V), it represents the potential difference or electrical pressure that drives the current through a conductor.
• Current (I): Measured in amperes (A), it represents the flow of electric charge through the conductor.
• Resistance (R): Measured in ohms (Ω), it represents the opposition to the flow of current within the conductor.

Ohm’s Law indicates that the voltage across a conductor is directly proportional to the current flowing through it, provided the resistance remains constant. This means that if the voltage increases, the current increases, provided the resistance stays the same. Conversely, if the resistance increases, the current decreases for a given voltage.

Calculating Power (P): In addition to Ohm’s Law, power in an electrical circuit can be calculated using the formula:

• Power (P): Measured in watts (W), it represents the rate at which electrical energy is converted into other forms of energy (e.g., heat, light).

By combining Ohm’s Law with the power formula, you can also express power in terms of resistance and current:

Or in terms of voltage and resistance:

These formulas are crucial for understanding how electrical components behave in a circuit and for designing circuits that operate efficiently and safely.

Georgiev G.Z., “Ohm’s Law Calculator”, [online] Available at: https://www.gigacalculator.com/calculators/ohms-law-calculator.php