Diodes and LEDs

A series of free GCSE/IGCSE Physics Notes and Lessons.

Diodes and LEDs
In these lessons, we will

• Describe and explain the shape of the current - potential difference graph for a diode.
• Describe what is meant by a light-emitting diode and explain why they are useful.

Diode
The current through the diode flows in one direction only. This is because the diode has a very high resistance in the reverse direction. Therefore, diodes are useful for controlling the flow of current in circuits.

Light-Emitting Diode (LED)
An LED gives off light when a current flows through. LEDs are an extremely energy-efficient source of light.

Diodes - IGCSE Physics
What are diodes? Describe a half-wave rectifier and a full wave rectifier for converting alternating current to direct current.

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