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Question
Five resistors of different resistances are connected together as shown in the figure. A 12 V battery is connected to the arrangement.
Calculate:
(i) the total resistance in the circuit
(ii) the total current flowing in the circuit.
Solution
(i) From given figure, R1 and R2 are parallel.
∵ `1/"R'" = 1/"R"_1 + 1/"R"_2`
`= 1/10 + 1/40 = 5/40 = 1/8`
∴ R' = 8 Ω
R3, R4 and R5 are also parallel,
∴ `1/"R''" = 1/"R"_3 + 1/"R"_4 + 1/"R"_5`
`= 1/30 + 1/20 + 1/60 = 6/60 = 1/10`
∴ R'' = 10 Ω
∴ Total resistance in the circuit
= R' R''
= 8 + 10 = 18 Ω
(ii) V = 12 volt.
∴ Total current flowing in the circuit ]
I = `"V"/"R" = 12/18`
`= 2/3 = 0.667` A.
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