V=IR relates voltage, current and resistance in a resistor.
V=IR states the voltage across a resistor is proportional to the current. Rearranged I=V/R or R=V/I. Applies to ohmic materials; diodes and filaments are non-ohmic. It is the most used equation in electrical work.
A 230 V heater of 46 Ω draws 5 A.
Ohm's law is the first relation every electrical calculation uses, so applying it correctly prevents overload and component damage.
V=IR relates voltage, current and resistance in a resistor.
Ohm's law is the first relation every electrical calculation uses, so applying it correctly prevents overload and component damage.
No. It applies to linear resistive devices. Diodes, lamps and transistors are nonlinear and need their own characteristic curves.
Ideal wires have zero resistance, so Ohm's law predicts infinite current for any voltage. Real wires have some resistance, but a short circuit can still cause very large currents.
Typical applications include calculating the current through an LED with a series resistor, finding the resistance of a heating element from voltage and current and estimating the current a battery supplies to a fixed resistive load.
Study "Resistance" first (topic 4 of 106 in Electrical Engineering). It covers the groundwork this topic builds on.
Straight-line I-V graph. Units: V, A, Ω. Combine with power formulas.
A 230 V heater of 46 Ω draws 5 A.
The next topic is "Electric power", which builds directly on this one.
It is classed as Beginner in Electrical Engineering (topic 5 of 106). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
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