Just done an experiment on ldrs. for some reasont he ohmage is coming out higher under extreme light. maybe i am just confused but the equation to wort out resitance would be r = v/i would it not.
My results for two volts on a power pack are 0.02 a and 3.47 v under bright light. this gives a big ohm reading but surely it should be smaller. it just doesnt make sense to me so any help would be appreciated.
Any advice on ldrs and resistors in a context of how and the theory of why they resist would be awesome.
Many Many thanks
2007-10-02 07:47:25 · 2 answers · asked by master 2 in Science & Mathematics ➔ Physics
The resistance should normally be very high, without light. High enough that no current will go through. Then in the light, the resistance is supposed to drop enough to let the current through.
The only thing I can think of is that you don't have enough light or there's something blocking it. Maybe your LDR is defective. I'm not sure.
Sorry man.
2007-10-02 08:04:54 · answer #1 · answered by Anonymous · 0⤊ 0⤋
I notice that you use "extreme" light. If so, additional heating of the element will raise the resistance, but I doubt it could be responsible for the magnitudes of the changes you're getting.
2007-10-02 15:11:15 · answer #2 · answered by supastremph 6 · 0⤊ 0⤋