How do you obtain electrons and know their average velocity?? Hello guys! I am currently trying to experiment with charge accelerators. I soon tripped inside a really big hole. I soon realized that I didn't know how to measure the amount of charge(in coulombs) a charged conductor has. So instead of using charged objects, I decided to use electrons. How would I go about obtaining electrons? Most importantly, how could I measure the average velocity of a beam of the electrons I obtained (if I am able to obtain them).