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Light Emitting Diode (LED)

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  Light Emitting Diode (LED) Introduction A Light Emitting Diode (LED) is a semiconductor device that converts electrical energy directly into light energy. It is a special type of PN junction diode that emits light when it is operated in the forward-bias condition . LEDs are widely used in electronic and electrical systems because they are small in size, consume less electrical power, have a long operating life, and can produce light in different colours. Common applications of LEDs include: Indicator lamps Digital displays Traffic signals Remote-control systems Automotive lighting Decorative lighting Street lighting Electronic instruments Television and computer displays Optical communication systems The basic principle behind LED operation is electroluminescence .   What is an LED? A Light Emitting Diode is a PN junction semiconductor device that emits visible or invisible light when current flows through it in the forward direction. T...

Online test-11th Physics - Units and Measurements Test

Online Test Online Test 1. What is the unit of Force? Joule Watt Newton Pascal 2. SI unit of Mass? Kilogram Gram Newton Meter 3. Speed = ? Distance × Time Distance / Time Time / Distance Mass × Acceleration 4. Unit of Pressure? Watt Newton Joule Pascal 5. Who discovered Gravity? Newton Einstein Galileo Faraday 6. Who discovered Gravity? Newton Einstein Galileo Faraday Submit