LED, photodiode and solar cell
Semiconductors · Physics
DC circuit
Interactive 3DElectrons drift around the loop — raise the voltage and watch the current obey Ohm's law.
Controls
Drag the sliders or type a value — the simulation updates live.
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Study notes
Example: An LED has a forward voltage of 2 V. It is connected to a 9 V battery through a resistor. Find the current through the LED if the resistor value is 470 Ω. Step 1: Calculate the voltage across the resistor: V_R = V_source - V_LED = 9 V - 2 V = 7 V. Step 2: Use Ohm's law to find the current: I = V_R / R = 7 V / 470 Ω ≈ 0.0149 A. Step 3: Convert to milliamps: I ≈ 14.9 mA. So about 15 mA flows through the LED, which is a safe operating current.