- #1
Bassalisk
- 947
- 2
Hello,
I did an experiment home, i took a power supply 9V and hooked it up in series with 1k Ohm resistor, then after that I hooked it up to a parallel connected 2 LED diodes. So both diodes were on the same voltage drop. I don't know exact calculations behind it but it doesn't matter. Here is the thing. I hooked a small metal wire to the one electrode of the LED diode, and I heated up that wire. That LED diode started glowing brighter and the other LED diode started dimming. Now this is against my intuition. I have 2 conflicts here.
I know that in semiconductor, when u give energy to it, u get more charge carriers ergo you can have more current. But today my professor told the same experiment, but with no heating, with light bulbs. He said that if one light bulb has more resistance, it will glow brighter. Of course, he was talking about AC current, but I don't think that matters.
Now how can this be? If resistance goes up, the current must go down! I=U/R! Can someone explain what is really going down with this phenomena? Are 2 cases(LED and bulbs) both explainable in the same fashion or is there a difference?
Thanks
I did an experiment home, i took a power supply 9V and hooked it up in series with 1k Ohm resistor, then after that I hooked it up to a parallel connected 2 LED diodes. So both diodes were on the same voltage drop. I don't know exact calculations behind it but it doesn't matter. Here is the thing. I hooked a small metal wire to the one electrode of the LED diode, and I heated up that wire. That LED diode started glowing brighter and the other LED diode started dimming. Now this is against my intuition. I have 2 conflicts here.
I know that in semiconductor, when u give energy to it, u get more charge carriers ergo you can have more current. But today my professor told the same experiment, but with no heating, with light bulbs. He said that if one light bulb has more resistance, it will glow brighter. Of course, he was talking about AC current, but I don't think that matters.
Now how can this be? If resistance goes up, the current must go down! I=U/R! Can someone explain what is really going down with this phenomena? Are 2 cases(LED and bulbs) both explainable in the same fashion or is there a difference?
Thanks