Ohm’s law
See how voltage, resistance and current are related.
At constant resistance, current is proportional to voltage; at constant voltage, current is inversely proportional to resistance. The moving dots in the circuit show the conventional current direction, and their speed reflects the size of the current.
Current vs. voltage
Think about it
Keeping the voltage constant, if the resistance is increased to 2 times its original value, how does the power change?
The power is halved. Since P = U²/R, at constant voltage the power is inversely proportional to the resistance.
Model assumptionsIdeal DC source · ohmic resistor · dot speed is illustrative
Data log
Set the parameters and click “Record data”. Record several rows with different parameters to plot their relationship and fit a straight line; pause and record at different times to study how a reading changes with time.