Uh good afternoon everyone. uh until mid400 the world was a humongous concept and uh with the invention of the printing machine the world started to shrink and over the period of time technological advancement brought a world in made the world very tiny space right it's it's a global village. So there was a time when electron used to transfer through this kind of device called vacuum tubes.I am sure none of you have seen except one or two seasoned professionals like me in their lifetime in engineering. Thes ...