(January 15, 2016 at 7:17 am)Alex K Wrote: Just some things that come to mind concerning your calculation -
It is conceivable that the 200W bulb will draw a bit more than 60W (i.e. (120/220)^2 times the power) at reduced voltage because the resistance will be noticeably lower at the new operating point as compared to 200W. Also, it is possible that the 200W bulb running with 60W will have lower filament temperature than a regular 60W bulb, thus reducing the efficiency in visible light, so there might be a trade off between longevity and efficiency. Those are just ideas, I don't know how big these effects are.
p.s. standard voltage has been 230V for some time now, at least in Germany
Yeah you're right about that - the filament resistance is variable to heat, therefore instead of 59.5W it could draw say 62W or something like, it's difficult to know exactly without running a measured test. What it won't be, however, is any less than 59.5W since heat increase the resistance in the filament.
For Religion & Health see:[/b][/size] Williams & Sternthal. (2007). Spirituality, religion and health: Evidence and research directions. Med. J. Aust., 186(10), S47-S50. -LINK
The WIN/Gallup End of Year Survey 2013 found the US was perceived to be the greatest threat to world peace by a huge margin, with 24% of respondents fearful of the US followed by: 8% for Pakistan, and 6% for China. This was followed by 5% each for: Afghanistan, Iran, Israel, North Korea. -LINK
"That's disgusting. There were clean athletes out there that have had their whole careers ruined by people like Lance Armstrong who just bended thoughts to fit their circumstances. He didn't look up cheating because he wanted to stop, he wanted to justify what he was doing and to keep that continuing on." - Nicole Cooke
The WIN/Gallup End of Year Survey 2013 found the US was perceived to be the greatest threat to world peace by a huge margin, with 24% of respondents fearful of the US followed by: 8% for Pakistan, and 6% for China. This was followed by 5% each for: Afghanistan, Iran, Israel, North Korea. -LINK
"That's disgusting. There were clean athletes out there that have had their whole careers ruined by people like Lance Armstrong who just bended thoughts to fit their circumstances. He didn't look up cheating because he wanted to stop, he wanted to justify what he was doing and to keep that continuing on." - Nicole Cooke
