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Ohm's Law (Why Do We Need Resistors?) | NexaLearn IoT Lab | NexaLearn

Electronics Basics25 دقيقة

Ohm's Law (Why Do We Need Resistors?)

Protecting LEDs from burning out with a simple understanding of current and voltage.

Lesson Content

Voltage (Volts) is the 'pressure' that pushes electricity. Current (Amps) is the amount of electricity flowing. Arduino provides 5V, while a small red LED only needs 2V and will try to draw a massive current that will burn it instantly. A resistor acts as a 'speed bump' that reduces current and consumes the excess voltage. Ohm's Law: V = I × R.

Components Needed

LEDمقاومات مختلفة القيم (220، 1K، 10K)بطارية أو أردوينو

Wiring Notes

Try connecting an LED with a 220 Ohm resistor and observe the brightness, then swap it for a 10K Ohm resistor and notice how the LED becomes very dim.

Code Example

// تجربة فيزيائية لا تحتاج لكود

Common Mistakes

Connecting an LED directly to 5V without a resistor — the LED will flash briefly then burn out, emitting a burning smell.

Next Lesson

Digital Input: Reading Buttons