How engineering works.

Clear explanations with interactive examples. Diagrams simplify reality and do not control any real equipment.

Ohm’s law

Voltage, current and resistance are related in a simple resistive circuit.

INTERACTIVE EXAMPLESIMULATION

The principle

For an ohmic resistor, U = I × R. Thus I = U / R and R = U / I. This describes a linear resistance under the given conditions; not all components behave this way.

An example

Adjust voltage and resistance to see the calculated current. For example, 12 V across 6 Ω produces 2 A.

Important

Real circuits also involve power, temperature, tolerances and maximum component ratings.

Technical source / documentation ↗