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Q & A: Wire resistance for heater elements?

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Most recent answer: 08/30/2009
Q:
for a constant voltage supply, according to the formula(v(raise to power 2)/r), we should use low value of resistance to get high energy, then y we used to use high rsistance wires for electrical heaters
- vivek (age 20)
kurukshetra,haryana,india
A:
Your formula for the power is correct.   However, there is a limit to the amount of power or amperage that a battery or house mains can supply.   If you use too low a resistance you will drain a battery quickly or blow out a fuse.   So what you do is to choose an acceptable power level, say 100 or 200 Watts, and then select the resistance to supply just this amount.

LeeH

(published on 08/30/2009)

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