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Here are our results:
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Electrical Resistance of Soil
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Soil Mixture
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Resistance in Ohms
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| Cup A: Soil saturated with salt water |
96,000 ohms |
| Cup B: Soil saturated with oil |
too high to measure |
| Cup C: Dry soil |
too high to measure |
We found that with dry soil the resistance was so high that the pointer of the ohmmeter did not move at all when we touched the probes to the two wires sticking out of the soil. We recorded the resistance as "too high to measure." This was also true for the soil saturated with oil. The salt water saturated soil had a resistance of 96,000 ohms. (This may also be written as 96K ohms. K stands for "Kilo" which is the prefix for 1000.)
Your results may be very different, but in general you will probably find that soil, sand, or gravel that is dry or soaked in oil has a very high resistance, while salt water saturated soil, sand, or gravel has a significantly lower resistance.
Click here to see the results that other people have gotten.
- If you did the experiment with soil, try using sand or gravel and compare your results.
- Compare the resistance of soil saturated in fresh water with that of soil saturated in salt water.
- Look at the experiments on the Absorbency of Rock. Before soaking each rock, touch the ohmmeter probes to opposite sides of it. What is the resistance? Check the resistance again after soaking it.
Send us your results. We'll periodically post new results on this site.
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