Does electricity travel through vacuum?If so ,is it a good conductor?What is its resistance.
What do you think? What do you mean by 'electricity'?
I mean the flow of electrons,i.e without any medium,can electricity flow?
Electrons are particles. They can travel through a vacuum.
Thank you very much.
And also, the vacuum is an insulator. It has infinite resistance. Usually.
If it has infinite resistance then how can electrons flow?
They won't naturally flow across a vacuum, as they would across a conductor. But they can be projected into a vacuum. (Look up electron gun, for details on that.) It's not clear from your question what context you are thinking of.
IF you can provide electrons (e.g. from a heated cathode) electrons will flow very easily through a vacuum because they will not bump into anything to slow them down. A thermionic diode conducts well 'one way' because of its hot cathode but the Anode has no heater so there are no electrons available to let the current flow the other way.
Bottom line is that it's not the vacuum that determines the effective 'resistance' it is the surface of the electrode that determines whether they are available or not.
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