How do you calculate resistance using V = IR?
Use the equation V = IR, where V is potential difference in volts, I is current in amps and R is resistance in ohms. To find resistance, rearrange to R = V ÷ I. Convert units first, such as milliamps to amps. For example, 12 V and 0.5 A give a resistance of 24 Ω.
Formula
V = I × R, so R = V ÷ I
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