Ohmsches Gesetz

Ohm's law: voltage, current and resistance

U = R·I links voltage, current and resistance of an ohmic load.

MINTSI

Inputs

Solve for

Voltage U (result)

Electrical potential difference across the load; measure directly or use the supply rating.

Current I

Current through the load. Fuse and conductor size limit the permissible value.

Resistance R

Ohmic load resistance; coils and semiconductors may vary with temperature or frequency.

Power P

Electrical real power. It is U·I and helps assess thermal loading.

Select a target and calculate.

Technical principle schematic

Calculation

U = R·I links voltage, current and resistance of an ohmic load.

Understand the inputs

Voltage U — Electrical potential difference across the load; measure directly or use the supply rating.
Current I — Current through the load. Fuse and conductor size limit the permissible value.
Resistance R — Ohmic load resistance; coils and semiconductors may vary with temperature or frequency.
Power P — Electrical real power. It is U·I and helps assess thermal loading.

Example

12 V and 2 A give 6 Ω and 24 W.

Assumptions and limits

DC or sinusoidal quantities with power factor 1; no inrush transients.

Sources