Eight 6.0-W Christmas tree lights are connected in series to each other and to a 220-V source.
What is the resistance of each bulb?
Express your answer to two significant figures and include the appropriate units.
physics question 3/4?
2021-04-13 12:36 pm
回答 (2)
2021-04-13 8:33 pm
Vl = V/n = 220/8 volt
Rl = Vl^2/Pl = 220^2/(64*6) = 130 ohm
Rl = Vl^2/Pl = 220^2/(64*6) = 130 ohm
2021-04-13 4:29 pm
8*6W = 48W. The source delivers 48W. We know Power P= V²/R so R = V²/P = 220²/(8*6W) = 1008.33333...Ω = 3025/3 Ω = the resistance of 8 bulbs in series so each bulb is about 3025/24 = 126Ω or about 130Ω <<<<<
Check
220V/(8*126Ω) = 0.22A
Power = V*i = 220V*0.22A = 48.4W Close enough.
OR we could do it this way:
Each bulb has 220/8 = 27.5V across it and 6W = 27.5²/R so R = 27.5²/6 = 126Ω
Same answer
Hope this helps. Please award Best Answer to the best answer. That is the only reward for efforts to help.
Check
220V/(8*126Ω) = 0.22A
Power = V*i = 220V*0.22A = 48.4W Close enough.
OR we could do it this way:
Each bulb has 220/8 = 27.5V across it and 6W = 27.5²/R so R = 27.5²/6 = 126Ω
Same answer
Hope this helps. Please award Best Answer to the best answer. That is the only reward for efforts to help.
收錄日期: 2021-04-24 08:40:54
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