Light dependent resistor experiment

AI Thread Summary
The discussion revolves around a physics coursework experiment using a light-dependent resistor (LDR) to investigate how water depth affects light absorption and resistance. The participant was unable to complete the experiment due to illness and is seeking clarification on the relationship between water depth and light absorption. Initial results indicate that as water depth increases, the rate of light absorption decreases, suggesting a non-linear relationship. Theoretical insights point to an exponential decay law governing light absorption with increasing depth. The participant expresses gratitude for the assistance received in understanding these concepts.
eymen23
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Homework Statement



Hi there I never managed to get a decent set of results in my physics coursework as I was unfortunately ill for the last few lessons of experiment time! My teacher won't let have an extension and won't let me do any more experimenting during lunch hours!
Basically by using an LDR I was looking at how the depth of water effect the resistance of the LDR (by measuring current) and hence finding out how depth of water affected the amount of light absorbed by the water. I know that obviously that the deeper the water is the the more light will be absorbed meaning the resistance of the LDR will be greater as less light will pass through the water however: I'm unsure as too whether the amount of light absorbed by the water is directly proportional to the depth or not. Could anyone help me...I did manage to get some results which suggested that as the water got deeper the rate at which light was absorbed decreased (as the water got deeper the difference in current between each depth decreased.)


Homework Equations

Ohm's law I=V/R comes into play, I am using a power pack to supply a constant 3 volt voltage to the circuit. So as resistance due to light absorption changes the current will also change.



The Attempt at a Solution



I think I've already outlined my attemt, it's simply I didnt have enough time to complete my experiment as enough different depths to draw an accurate conclusion to how light absorption is affected by depth, so was wondering if anyone on here could help??
 
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Welcome to PF.

The amount of light should follow an exponential decay law, as depth is increased.
 
Thank you! Very helpful of you, couldn't find any information online anywhere!
 
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