I have a question which has intrigued me for quite some time. If the electrons are accelerated using a potential difference in a cathode ray tube, the electrons should get accelerated till the time they reach the anode only. Once they cross over (ie. move to the other side of the anode), they should begin to slow down, now being attracted by the anode. Hence, on the whole, I suppose there should be no net gain in energy for the electrons, unless the anode is placed very close to the front glass screen of the CRT, in which case there's not enough time available to the electron to be slowed down appreciably. This is a conundrum for me. Can anyone explain this?