In the photoelectric effect, electrons are liberated from the cathode at a certain rate which is independent of the external voltage applied. I understand the relationship between voltage and current if I think of current as the rate of electrons hitting the anode. When increasing voltage, I understand that the rate of electrons hitting the anode remains the same since this is solely determined by the rate of electrons leaving the cathode and not the speed of the electrons.
However, my understanding breaks down when I try to understand current as the flow of electrons through the wires themselves.
- By increasing voltage, the electrons moving in the wires will have greater speeds and reach the cathode faster. Hence, how is it possible for the current to be the same in the wires?
- When voltage is constant, how is it possible for the current to be the same everywhere in the wires? Where does the extra energy go, since a stronger field has been established?
I think part of the problem may be my conflation of speed vs rate at which electrons leave the cathode. Any help will be greatly appreciated.