What is Ohm's Law?
Ohm's Law states that the voltage (V) across a conductor is directly proportional to the current (I) flowing through it, with the constant of proportionality being the resistance (R). Expressed as V = I × R, this fundamental principle, discovered by Georg Simon Ohm in 1827, describes the linear relationship in most electrical circuits under constant temperature.
Key Principles and Components
The law's core components are voltage (measured in volts), current (in amperes), and resistance (in ohms). It assumes ohmic conductors where resistance remains constant. Rearrangements allow solving for any variable: I = V / R or R = V / I. This linearity holds for materials like metals but not for non-ohmic devices like diodes.
Practical Example in Circuits
Consider a simple circuit with a 12V battery and a 4-ohm resistor. Using V = I × R, the current is I = 12 / 4 = 3A. If you add another 4-ohm resistor in series, total resistance becomes 8 ohms, reducing current to 1.5A. This example shows how Ohm's Law helps predict and design safe circuit behavior.
Applications and Importance
Ohm's Law is essential in electronics for designing circuits, calculating power dissipation (P = I²R), and troubleshooting devices like resistors in LEDs or household wiring. It's applied in automotive systems, power supplies, and sensors, ensuring efficiency and safety by preventing overloads in real-world engineering.