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Physics problem about electric power 220V 100W In 110 V circuit Find r =? P=? Heat generated in 1min? Please write down the detailed process (formula used) Please, we have to write the process
P = u ^ 2 / r r = u ^ 2 / P = 220 ^ 2 / 100 = 484 Ω
P'=U'^2/R=110^2/484=25W
Q=U^2t/R=p't=25*60=1500J
A physical problem about electric power
A lighting bulb marked with "220 V 100 W" is connected to a remote construction site with a wire. The power supply voltage is 220 v. because the wire resistance is large, six watts of electric power is consumed on the wire. Then the actual power of the small bulb (the filament resistance does not change with the temperature) can be explained in detail
If the voltage of wire is U1, current I = P / U1, lamp resistance R2 = u ^ 2 / P = 484 ohm, 220 = U1 + (P / U1) * 484 ohm
Calculate U1, then 220-u1 is the actual voltage of the bulb, and then p = u ^ 2 / R is used to calculate the actual power of the bulb
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