Make the connection
Ohm’s law & power
Explore how voltage and resistance determine current and electrical power.
Ohm’s law & powerTRY IT YOURSELF
Current0.12 A
Power1.44 W
Voltage12 V
Resistance100 Ω
Teal + amber · follow the changing valuesIdealized physics model
What if you changed…
Try a starting point
Double the voltage. What happens to current? What happens to power?
See the calculation
V = IR · P = VI
- I = V/R = 12/100 = 0.12 A.
- P = VI = 12 × 0.12 = 1.44 W.
What this model assumes
Ideal DC voltage source and an ohmic resistor with constant resistance; wires have zero resistance.
Keep an eye on this
Real components have power ratings and may heat up; this educational model is not a circuit safety check.
Understand the physics ↗A little question. A clearer picture.
Ohm’s law & power: common questions
Wondering about the why? Start here.
What happens when resistance increases?
At fixed voltage, current decreases because I = V/R. Power also decreases as V²/R.
Why is zero resistance not allowed?
An ideal source connected across zero resistance would demand an unbounded current. Real circuits have internal resistance and other limits.