======Electrostatic Deflection of a Water Stream======


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**Alternative titles:** Bending Water with Static Electricity
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====Summary====                   
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====Procedure====  
  - Mount a plastic cup with a small hole in its base on a retort stand above a collection tray.  
  - Fill the cup with water so that a thin, continuous stream falls into the tray.  
  - Charge a plastic rod (or charging wand) by rubbing it with fur or wool.  
  - Bring the charged rod close to the falling water stream without touching it.  
  - Observe how the stream bends toward the rod due to the attraction of water molecules.



====Links==== 
Deflection of water by a charged rod (NCPQ) - Dr Richard Walding: 
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Water deflection demonstration - SiouxScience: 
{{youtube>57JYGYekhiM?}}\\

📄 Electrostatic Deflection of Water Stream - The University of Melbourne: [[https://physics.unimelb.edu.au/lecture-demonstrations/electricity-and-magnetism/miscellaneous/el-18-electrostatic-deflection-of-water-stream]]\\

====Variations====
  * Use different materials for charging (e.g., glass rod with silk, PVC rod with wool, balloon rubbed on hair) and compare effectiveness.  
  * Test other polar liquids (e.g., alcohol, vinegar) to see if they also deflect.  
  * Try non-polar liquids such as oil to show the absence of deflection.  
  * Vary the size of the hole in the cup to produce thinner or thicker water streams and compare the effect.  




====Safety Precautions====
  * Ensure water is collected safely in a tray to avoid spills on the floor.  
  * Keep electrical equipment away from the demonstration area.  
  * Handle the stand and cup carefully to prevent tipping.




====Questions to Consider====
  * Why does the water stream bend toward the charged rod? (Because water molecules are polar; they align with and are attracted to the electric field.)  
  * Why does oil not show the same effect? (Oil molecules are non-polar and are not strongly influenced by an electric field.)  
  * What real-world applications use this principle? (Electrostatic precipitation, inkjet printing, and some spray technologies.)  
  * How would the deflection change if the water stream were larger in diameter? (A larger mass of water resists deflection, so the effect would be smaller.)