A vacuum tube controls the flow of electrons that pass through it. In order to create a vacuum nearly all of the air must be removed from the tube. What advantages do you think is gained by removing air from the space in which electrons will be traveling?

Question

Thanks!

Answer 1

At least two that I can think of.
1. Electrons don't bump into air molecules.
2. Oxygen is not available to oxidize the filament(s) of the vacuum tubes.