How does water volume affect electrical resistance?

In summary, the conversation discusses a potential school physics project involving measuring the volume of water in a fixed shape container using electrical current and monitoring resistance changes. The idea is to connect two electrodes at the bottom of the container and observe a drop in resistance as more water is added. However, there may be issues with using pure water as it does not conduct electricity well, and the potential divider circuit may result in electroplating effects. The project may work for a short period of time but may not be very linear if the container is tall.
  • #1
perfectsphere
1
0
Hi, I've had an idea for a school physics project but I'm not sure if it will work.
I want to measure the volume of water in a fixed shape container by passing an electrical current though it and monitoring how the resistance changes (with a potential divider circuit). My idea is that if I connect two electrodes at the opposite ends of the bottom of the container and then add more water to the container, the resistance would drop. I got this from how a thicker wire has less resistance than a thinner wire. However, I'm guessing that water doesn't work in the same way as metal wire so I would really value your opinions on how you think this will or won't work.
Thanks!
 
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  • #2
Pure water doesn't conduct electricity very well but otherwise it should work. It might not be very linear if your container is very tall.

Edit: I forgot to add that if you use a potential divider circuit one of the electrodes will be at a higher voltage than the other. This may result in electroplating effects (eg one electrode dissolves). This is unlikely to be a problem if you only need it to work for few days.
 

1. How does increasing water volume affect electrical resistance?

Increasing water volume can increase the electrical resistance of a material. Water molecules are polar, meaning they have a positive and negative end, and they can disrupt the flow of electrons through a material. As the amount of water increases, there are more molecules to interact with the electrons, leading to a higher resistance.

2. Does the type of water affect the electrical resistance?

Yes, the type of water can affect the electrical resistance. Distilled water, which has a low concentration of ions, will have a higher resistance compared to tap water or saltwater, which contain more ions. This is because ions can act as conductors and decrease the resistance of the water.

3. How does temperature impact the relationship between water volume and electrical resistance?

The relationship between water volume and electrical resistance is affected by temperature. As the temperature increases, the molecules of water gain more energy and are able to move around more easily. This can decrease the resistance of the water, making it easier for electricity to flow through.

4. Is there a limit to how much water volume can affect electrical resistance?

Yes, there is a limit to how much water volume can affect electrical resistance. This is because at a certain point, adding more water will not significantly increase the number of water molecules present to interact with the electrons. This means that the resistance will reach a plateau and no longer increase with more water volume.

5. Can changing the shape or size of a container holding water affect the electrical resistance?

Yes, changing the shape or size of a container holding water can affect the electrical resistance. This is because the shape and size can impact the amount of water present and how it is distributed. For example, a longer, narrower container will have a higher resistance compared to a shorter, wider container with the same volume of water.

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