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Question
A combination consists of three resistors in series. Four similar sets are connected in parallel. If the resistance of each resistor is 2 ohm, find the resistance of the combination.
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Solution
Resistance of each set:
1r = 2 + 2 + 2 = 6 ohm
2r = 2 + 2 + 2 = 6 ohm
3r = 2 + 2 + 2 = 6 ohm
4r = 2 + 2 + 2 = 6 ohm
Now these resistances are arranged in parallel :
`1/r=1/r_1+1/r_2+1/r_3+1/r_4`
`1/r=1/6+1/6+1/6+1/6`
`r=6/4=1.5 ohm `
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