Question 1

How do you calculate LED resistor value?

Accepted Answer

R = (V_supply - V_LED) ÷ I_LED. A 5V supply with 2V red LED at 20mA needs (5-2)/0.02 = 150Ω resistor.

Question 2

What happens without an LED resistor?

Accepted Answer

LED draws excessive current and burns out. LEDs need current limiting because they have very low resistance.

Question 3

What's the relationship between volts, amps, and watts?

Accepted Answer

Power (Watts) = Voltage (Volts) × Current (Amps). To find any value, divide or multiply: Amps = Watts/Volts, Volts = Watts/Amps.

Question 4

Is AWG or metric wire gauge better?

Accepted Answer

AWG (American Wire Gauge) uses arbitrary numbers where smaller = thicker. Metric (mm²) directly indicates cross-sectional area, making calculations easier.

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