Question

What are light emitting diodes? Describe the principle and working of a light emitting diode. Why are they more useful than traditional filament lamps?

Hint:

LEDs are energy-efficient, have a long lifespan, and emit less heat compared to traditional filament lamps, making them ideal for modern lighting applications.

Answer 1

Step 1: Light Emitting Diodes (LEDs).
A Light Emitting Diode (LED) is a semiconductor device that emits light when an electric current passes through it. LEDs are made of materials that allow current to flow in only one direction and produce light by electroluminescence.
Step 2: Principle and Working of LED.
When a forward voltage is applied to an LED, electrons recombine with holes in the semiconductor material. As the electrons drop to lower energy levels, they release energy in the form of photons, producing light. The color of the light depends on the energy band gap of the semiconductor material.
Step 3: Advantages Over Traditional Filament Lamps.
LEDs are more energy efficient than traditional filament lamps because they produce less heat and convert more electrical energy into light. They also have a longer lifespan and are more durable. Unlike filament lamps, LEDs do not burn out or break easily. Moreover, LEDs are smaller in size, which allows for more compact lighting solutions.