Electronics/Ohm's Law

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Ohm's law describes the relationship between voltage, current, and resistance.

Voltage and current are related such that voltage is equal to current times resistance:

V = I \cdot R

Common units used in electronics calculations are:

V = mA × kΩ

Ohms law voltage source.svg

In this example, the current going through any point in the circuit, I, will be equal to the voltage V divided by the resistance R.

Ohms law current source.svg

In this example, the voltage across the resistor, V, will be equal to the supplied current, I, times the resistance R.

SUMMARY:

V=I times R
I=V divided by R
R=V divided by I