Ohm's Law
Understanding the fundamental relationship between voltage, current, and resistance.
What is Ohm's Law?
Ohm's Law is a fundamental principle in electrical engineering that describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. It states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them.
Ohm's Law Formulas
I = V / R (Current = Voltage / Resistance)
R = V / I (Resistance = Voltage / Current)
Where:
• V = Voltage in Volts (V)
• I = Current in Amperes (A)
• R = Resistance in Ohms (Ω)
Ohm's Law Triangle
A common mnemonic for remembering Ohm's Law formulas is the Ohm's Law triangle:
Cover the quantity you want to find, and the remaining two quantities show the formula.
Applications of Ohm's Law
| Application | Description |
|---|---|
| Circuit Analysis | Calculating unknown values in simple and complex circuits. |
| Resistor Sizing | Determining the correct resistance for current limiting or voltage division. |
| Power Calculation | Used in conjunction with power formulas (P = V × I) to determine power dissipation. |
| Troubleshooting | Diagnosing faults in circuits by measuring and comparing values. |
Frequently Asked Questions
Who formulated Ohm's Law?
Ohm's Law was formulated by German physicist Georg Simon Ohm and published in 1827.
Does Ohm's Law apply to all materials?
Ohm's Law applies to ohmic materials, where resistance remains constant regardless of voltage or current. Non-ohmic materials (like diodes or transistors) do not follow Ohm's Law linearly.