Electrons are emitted from cathode C and accelerated towards anode A. http://img526.imageshack.us/img526/7655/efield.jpg [Broken] Anode is earthed. Electric field strength along CA is shown. Question: Arrow of direction of electric field along CA. My ans would be left to right as I thought e-fields are always from high to low potentials? But the answer says opposite as electrons experience an electric force opposite in the direction to the electric field (which I know is correct). Anyone can help answer my querry? Why isnt looking at high to low potential in the graph correct? Thanks.