Diode is made of two different parts. One part is called p-type and other part is called n-type. In between, we call it the p-n junction. P-type is silicon mixed with boron, and n-type is silicon mixed with phosphorous. In order to explain how it works, we must know about the octet rule and valence electrons.
The octet rule is that bonded nonmetialic atoms has eight electron outermost shell or energy level. It means that when two chemicals react each other and produce a product, its outer shell has eight electrons.
The valence electrons are the electrons moving aroung the most outer shell of an individual atom and they are often involved into chemical reaction bonding.
Read more about diode.
(LED and the symbol of LED)
LED emission is visible in the spectrum wavelengths from 0.4 to 0.7m or in the near infrared, which we cannot see, that of wavelengths between 2.0 and 0.7 m. More than 20 billion LEDs are produced each year.
This device is used in digital circuit such as computer memories. Computer memories can be lost during electric power failure, so the capacitor provides power to maintain information from temporarily loss of power.
(Capacitor and its symbol)
(Photo resistor and its symbol)
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