In this video i have discussed the working principle of a basic current mirror also know as wilson current source
This topic is usually taught in B TECH. fifth semester of electrical engineering.
Books i recommend for studying this topic:-
1.Microelectronic Circuits by Sedra & Smith
2.Linear Integrated Circuits by D Roy Choudhury
3. microelectronics by Behzad Razavi
pdf link for sedra smith and d roy --
https://mega.nz/#F!qNlBnApI!OWre-0eeZ...
If you have any doubts post them in the comment section i will be happy to help.
THANK YOU