Why are electrons attracted to a positively charged anode in an electron tube?

In an electron tube, electrons are attracted to the anode because they carry a negative electric charge, and fundamental physical principles dictate that opposite electric charges attract one another.12

When a voltage is applied between the electrodes in the tube, it establishes an electric field. Because the anode is maintained at a positive potential relative to the cathode, this field exerts an attractive force on the negatively charged electrons emitted by the cathode. This force accelerates the electrons toward the anode, creating a flow of current through the tube. If the anode were negatively charged, it would instead repel the electrons, preventing this current from flowing.34