I want to check some lamps by testing their outpu at different wavelengths, and I HAVE to use an LDR in my experiment. Also, how does the intensity of light vary with wavelength?
2007-04-19 04:45:27 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Intensity of light is completely independant of wavelength. The only time intensity is a function of frequency is in a blackbody radiator (or facsimile, thereof).
If you have narrowband light sources (LEDs, LASERs), then intensity is truly independant of frequency. If you have wideband light sources (tungsten filaments, fluorescent lamps, etc), then they have some blackbody characteristics and do have intensity vs. frequency curves.
The other thing that is very important is the LDR itself. The LDR has its own intensity vs frequency characteristic. You have to account for that in your experiments.
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2007-04-19 04:53:53 · answer #1 · answered by tlbs101 7 · 1⤊ 0⤋
Depends on what flavour of LDR. If it's an old Cadmium Sulphide one I wouldn't expect much difference, or if there was it would be difficult to measure. Also the older ones have a glass facia which means higher frequencies are going to be attenuated. If it's a silicon based one then the higher frequency lights should give decreased resistance due to the higher energy level exciting electrons more.
2007-04-19 04:54:52 · answer #2 · answered by Del Piero 10 7 · 0⤊ 0⤋
The LDR resistance varies only with the intensity not by changing the frecuency. The intensity of the light doesn't vary with the wavelenght.
2007-04-19 04:57:57 · answer #3 · answered by jaime r 4 · 0⤊ 0⤋
hi a mild based resistor (LDR) is only that. particularly while gentle photons hit a mix of gear it aggravates electron circulate which decreases resistance to electric powered present day.
2016-11-25 22:09:04 · answer #4 · answered by kostenbauber 4 · 0⤊ 0⤋