How voltage, current and resistance are related in an ideal resistive model.
What is Ohm's law?
Ohm's law states that for an ideal ohmic component, V = I R.
Voltage is measured in volts, current in amperes and resistance in ohms.
The same relationship can be rearranged as I = V/R and R = V/I.
What does it explain?
Ohm's law lets engineers predict current through a resistor, voltage drops in a circuit and power dissipation.
Combined with Kirchhoff's laws, it supports the analysis of large networks.
What are its limits?
Ohm's law is not a law that every component obeys at every moment. A diode, transistor, battery, filament lamp or biological tissue may have a nonlinear or changing current-voltage relationship.
Even a resistor changes with temperature and frequency.
Why is it valuable?
It is a compact model with enormous practical use. Its value comes from knowing when its assumptions apply and when a richer model is needed.
Ai disclosure: written with the help of AI (ChatGPT). You are encouraged to point out errors and omissions.  
