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A 20 Ω light bulb is designed for use in a 14V source but instead it is placed in a circuit with a 18V source.?
What amount of resistance needs to be used, and how should it be connected to the
circuit, to operate this bulb for what it was designed for? You need to show a diagram for this.
1 Answer
- oldschoolLv 77 days agoFavorite Answer
The bulb is designed to function with 14V or 14V/20Ω = 0.7A
18/(20+R) = 0.7A so 18 = 20*0.7 + 0.7*R so R = (18 - 20*0.7)/0.7 = 40/7 Ω
A resistance R = 40/7 or about 5.7Ω added in series with the 20Ω bulb.
Check
18/(20+40/7) = 18/(180/7) = 126/180 = 63/90 = 0.7A Checks.
