# How is electric field effected by loss of energy of charge?

Recently, I asked a question related to energy of a charge(This is the question).

In one of the answers, in the comments section, I got an answer that the strength of the electric field is lessened if I put many bulbs in a single circuit. I want to ask just two questions here(I am sorry if this is a repetition, I am not able to understand some theories):

What are the factors that effect the strength of an electric field? Suppose I put 5 bulbs in a single circuit, the resistivity will be high, so less current flow, but what happens to the field? Will the charges not get constant energy due to the field?

Additional question: Suppose, those 5 bulbs take all the energy of the charge. Now, assuming the electric field to still be there, the charge regains some more energy. Now, will it be able to do light up any more bulbs(or run any other appliance) with that energy that it gains from the field?

I request the viewers not to give answers of any other question, I am hoping for a direct answer. And the answer to the first question is preferred more over the second question, because I think if I understand the first case better, I can understand the second case myself.

At the beginning let us talk about water. Water consists of molecules. There are two buckets, one of them is on the level 0 meters and one is on the level 1 meter. I fill the high-level-bucket with water and connect the two buckets with a small pipe. It takes 10 sec and all the water is in the low-level-bucket. How I have to relate the molecules properties to this process?

This molecules consists particles and feel the gravitational force and are able to fall down. The filled high-level-bucket could be a source of kinetic energy. It is a source in the case, I place a second bucket below the first and connect them with a pipe. Is the molecule the same, after falling down? Does it consists particles? Yes, it is and only the potential energy, which was given to them during the load into the high-level-bucket was converted to kinetic energy during the fall through the tube. So what is the difference to a electric current?

Instead of the high difference below the earth in a electric circuit one has to collect electrons in a source. This can happens by chemical reactions (battery, accumulator) or with an electric generator. One property of the electrons is to have a permanent electric field. The electric generator nor a battery do change this property. This devices only potential sources (the high-level-bucket). To release the energy, contained in the collected electrons one need the low-level-bucket and a pipe. The low-level-bucket is called a sink and this sink naturally is available because the sum of the electric charges from electrons and protons is a constant number. Every time, one fill a source with electrons, one make a sink too.

Now connect your source with the sink by a wire and the electrons will flow. This happens not due to a gravitational force of course but due to the repealing electrostatic forces in the source (to much electrons) and attracting forces from the sink (to much protons). The electric field of each electron stays unchanged.

Coming back to the buckets, when you take a very thin tube, you will see that the time for filling the low-level-bucket will be proportional langer as the cross-section of the tube will be smaller. Your water molecules are flowing slower (but their intrinsic properties are unchanged). You have losses in the tube due to friction and other phenomenons. The same for our electric circuit.

A thin wire will be heated up by the flowing electrons, you get heat instead of something else you wanted to do with the electric potential difference. Putting three bulbs in line you decrease the amount of electrons flowing in the wire, the bulbs convert less energy per time unit into heat and the source longer works until it exhausts. Short the source with the sink with a thick wire you let the electrons in a bigger amount and the source exhausts fast. Anyway, the intrinsic property of the electrons - their electric field - stays the same.

It is not easy to answer a question that has wrong presumptions or formulations like "loss of energy of charge". To answer your question I have to re-formulate your question but I think it is up to analyse it and to comment it by yourself.

What are the factors that effect the strength of an electric field? Suppose I put 5 bulbs in a single circuit, the resistivity will be high, so less current flow, but what happens to the field? Will the charges not get constant energy due to the field?

The factors vary depending on the source of non-EM electromotive force in the circuit.

For example, if the current is due to a battery and is not varying in time, the electric field will be constant and can be thought of as Coulomb electrostatic field due to electric charges distributed in the battery and the circuit itself (most of the relevant charge should be on their surface).

Batteries in such circuits usually maintain constant potential difference of the above field across the terminals. So whatever passive elements are connected in series in the circuit, the line integral of electric field is the same.

This means if you make the circuit longer, the electric field will get lower.

Also, if you have some foreign element connected in the circuit, such as section of thinner wire or other high-resistance element like a bulb, electric field inside this element may get higher than outside the element, because current is the same but current density is higher, and because of the Ohm law

$$\mathbf j = \sigma \mathbf E$$

where $\mathbf j$ is current density, $\sigma$ is material constant and $\mathbf E$ electric field, this can happen only if the electric field is higher than outside the element. The additional field is due to localized charges on the terminals of the element.