How Does Light Wavelength Affect LDR Output in Plant Growth Lamps?

AI Thread Summary
The discussion focuses on planning an experiment to assess how different light wavelengths from growth lamps affect the output of a light-dependent resistor (LDR). The experiment involves using colored filters to control the light wavelength and a CdS cell as the standard LDR. Key considerations include determining the appropriate distance between the light source and the LDR, as this affects photon arrival and signal strength. It is suggested to start at a distance and gradually move the LDR closer while measuring the output. Additionally, placing the filter closer to the LDR rather than the light source may yield more accurate results.
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Homework Statement


it is a reasearch project i have to plan an experiment to find what effect different wavelengths of light, from a lamp which is used to grow plants, will have on the output of an LDR.


Homework Equations





The Attempt at a Solution



so far my plan is (breifly) to use a lamp and put coloured filters in front of it to controll the wavelength. also i have researched a CdS cell which would be the standard lab LDR i will use. The only thing i really need help with is a proximate ranges for meters required. as i have bin looking for days and can't find anything that would help, i am using an ammeter and voltmeter to give the power output. "P=VI"
 
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The only thing i really need help with is a proximate ranges for meters required.
The distance between light source and LDR (light dependent resistor) would determine the number of photons arriving at the LDR, by virtue of the area * photon flux.

One could start some distance away from the light source and gradually move the LDR closer and measure the response or signal strength.


This might provide some insight - http://www.doctronics.co.uk/ldr_sensors.htm

The filtering will also affect the flux since it will 'filter out' some fraction of the photons. It would perhaps be better to place the filter nearer to the detecting LDR rather than the source.
 
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