engineering

Ohm's Law

The relationship between voltage, current, and resistance in an electrical circuit: V = I × R.

Ohm's Law is the foundation of electrical engineering: V = I × R

  • V (Voltage) = electrical potential difference, measured in Volts
  • I (Current) = flow of charge, measured in Amperes
  • R (Resistance) = opposition to current flow, measured in Ohms (Ω)

Rearranged Forms

  • I = V ÷ R (find current)
  • R = V ÷ I (find resistance)

Example

A 12V battery powers a 4Ω resistor. Current = 12 ÷ 4 = 3 Amps.

Power Formula

P = V × I. At 12V and 3A, power = 36 Watts.

Related Calculators

📊 Ohms Law Calculator📊 Voltage Calculator

Related Terms

Kilowatt-Hour (kWh)

A unit of energy equal to using 1,000 watts of power for one hour.

Torque

A rotational force that causes an object to rotate around an axis, measured in newton-meters or foot-pounds.

BTU (British Thermal Unit)

A unit of heat energy equal to the amount needed to raise one pound of water by one degree Fahrenheit.

Thermal Conductivity

A material property that measures how well it conducts heat, expressed in watts per meter-kelvin (W/m·K).

Specific Heat Capacity

The amount of heat energy required to raise the temperature of one unit mass of a substance by one degree.

Stress and Strain

Stress is the internal force per unit area in a material; strain is the resulting deformation (change in shape or size).