Ohm's Law Calculator Formula
Understand the math behind the ohm's law calculator. Each variable explained with a worked example.
Formulas Used
Voltage
voltage = current * resistancePower
power = pow(current, 2) * resistanceVariables
| Variable | Description | Default |
|---|---|---|
current | Current(A) | 2 |
resistance | Resistance(Ω) | 10 |
How It Works
Ohm's Law
Ohm's law is the foundational relationship in circuit analysis, connecting voltage, current, and resistance.
Formula
V = I * R
where V is voltage in volts, I is current in amperes, and R is resistance in ohms. Power dissipated is P = I² * R.
Worked Example
2 amperes flowing through a 10 ohm resistor.
- 01V = I * R
- 02V = 2 * 10
- 03V = 20 V
- 04P = I² * R = 4 * 10 = 40 W
Frequently Asked Questions
Does Ohm's law apply to all materials?
No. Ohm's law applies to ohmic materials where resistance is constant. Non-ohmic devices like diodes and transistors have nonlinear V-I relationships.
What is resistance?
Resistance is the opposition to current flow, measured in ohms. It depends on the material, length, cross-section, and temperature of the conductor.
Can Ohm's law be used for AC circuits?
For AC, impedance (Z) replaces resistance: V = I * Z. Impedance includes resistance plus reactance from capacitors and inductors.
Learn More
Guide
Ohm's Law Guide
A complete guide to Ohm's Law. Learn the relationship between voltage, current, and resistance, with practical examples, the power triangle, and circuit analysis tips.
Ready to run the numbers?
Open Ohm's Law Calculator