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प्रश्न
Show how would you join three resistors, each of resistance 9 Ω so that the equivalent resistance of the combination is
1) 13.5
2) 6 Ω
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उत्तर
1) Case: To get equivalent resistance = 13.5 Ω
For this case, two 9 Ω resistors should be first connected in parallel and then their combination should be connected in series with the remaining 9 Ω resistor. Thus,
`R = (9xx9)/(9+9) = 81/18` = 4.5 Ω
`R_"total"` = R + 9 = 4.5 + 9 = 13.5 Ω
2) Case: To get equivalent resistance = 6 Ω
For this case, two 9 Ω resistors should be first connected in series and then this combination should be connected in parallel with the remaining 9 Ω resistor. Thus,
R1 = 9 + 9 = 18 Ω
`R_"total" = (R_1xxR)/(R_1+R) = (18xx9)/(18+9)` = 6 Ω
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