Question

With the help of a diagram, show the biasing of a Light Emitting Diode (LED). Give its two advantages over conventional incandescent lamps.

Answer 1

Hint: Light emitting diode is a type of semiconductor device in which when current flows through it. Diode emits photons which in result produce light. When current and the material of a semiconductor combine it produces light in the device.

Complete answer:
Let us first draw a diagram which shows the biasing of Light Emitting Diode (LED).

In p-type region Holes are present and in n-type region there are electrons and when battery is connected in forward biasing such that positive terminal of battery connected to p-type region and negative terminal of battery connected with n-type region, this is called forward biasing. The thickness of the depletion layer becomes narrow and light is emitted through the semiconductor device.

Advantages of Light emitting diode over incandescent lamp:
$1.$ Since Light Emitting Diode works on the principle of Semiconductors hence LEDs are much more energy efficient than incandescent lamps and hence are generally used in households for low power generating.
$2.$ Very effective maintenance. Since LEDs are replaceable which minimizes its cost and hence it’s eco-friendly and no harm to the environment as compared to ordinary lamps.

Note:Depletion layer is a region in semiconductor diodes when holes of one region and electrons of another region together diffuse each other and some part of the diode becomes neutral which is called depletion layer. In forward biasing, depletion layer gets decreased whereas in reverse bias depletion layer gets increased.