This is a really confusing question for me. Suppose, there is an electric circuit. And, right near to the negative terminal of the battery, I place 3 bulbs, which would take almost all the energy of the electrons(energised charge). Now, if the charge looses all of the energy, will it not stop? But if it stops, it is still under the influence of the electric field, so it should move towards the positive terminal, and because it is in the field, it still has some potential energy.
So my question:
If what I just said is right, will the charge not have infinite energy
until it moves towards the positive terminal(because of the electric
force)? But if this is true, shouldn't infinite bulbs light up in the
circuit?If I am wrong, then what happens to the charge when it looses its
energy? What happens to the electric field?
Best Answer
The motion of the charges is totally unlike you setting off from home walking 10 km and feeling a little tired and slowing down and then walking another 10 km and feeling even more tired and slowing down and then walking a final 10 km and arriving home at a very slow pace, indeed just reaching your front door and stopping.
Here is a simple model of what happens.
The battery sets up an electric field inside the wires.
The mobile charge carries, the free electrons which are responsible for electrical conduction, are accelerated by this electric field and gain kinetic energy. Whilst in a bulb, any one of the three, the free electrons collide with the bound ions and give those bound ions some kinetic energy.
Then before another collision with a bound ion the free electron gains some more kinetic energy from the electric field to then give some to the next bound ion it meets.
The net effect of all this is that the free electrons have an average velocity (drift velocity) and the bound ions vibrate more, their "temperature" increases. The battery is the source of the energy which ultimately resides with the bound ions. The free electrons are just the mechanism by which the energy is transferred. Even if a free electron lost all of its kinetic energy it can then take some more from the electric field so it will never be marooned.