RRB Group-D Model Paper 13 with answers for online practice

• The full form of LED is Light Emitting Diode.

LED:

• It is an optical semiconductor device that emits light when voltage is applied means it converts electrical energy into light energy.
• Light Emitting Diode (LED) works only in forward bias conditions.
• When Light Emitting Diode (LED) is forward biased, the free electrons from the n-side and the holes from the p-side are pushed towards the junction.
• Light-emitting diodes emit either visible light or invisible infrared light when forward biased.
• The LEDs which emit invisible infrared light are used for remote controls.
• LEDs that can emit red, yellow, orange, green and blue light are available for commercial use.