But there is a tolerance for the resistor, let us measure the resistor.
The measured resistance in this figure is 8.2 Ω.
If we calculate it again using Ohm’s law ” “
𝑉 = 𝐼 · 𝑅
1. 887 𝑉 = 𝐼 · 8. 2 Ω
𝐼 =
1.887 𝑉
8.2 Ω
= 0. 230 𝐴 = 230 𝑚𝐴
So, we can count on this way to measure the current, 230 mA is near the value 238 mA.
8.5 Choosing the Right Resistor for an LED
To calculate the resistor for an LED, we need to know the forward voltage for the LED, LEDs are
different from the resistors, we need to limit the current passing through it because it does not work on
Ohm’s law.
35
Mastering the Art of Measurement (DM401B Smart Digital Multimeter) r.01 www.plusivo.com
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