Quick questions on Light-emitting diodes explained: O-Level Electronics Electronic Components

1short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is the LED forward voltage?

Show answer

An LED does not light until the forward voltage reaches its turn-on value, which depends on the colour but is typically about

2\ \text{V}

(higher for blue and white). Once conducting, it holds roughly this forward voltage across itself, just as a silicon diode holds about

0.7\ \text{V}

. This forward drop must be subtracted from the supply when sizing the series resistor.

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All ElectronicsQ&A pages