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Question
In the following figure calculate:
- the total resistance of the circuit
- the value of R, and
- the current flowing in R.
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Solution
(a) V = 4 V; I = 0.4 A
Total Resistance R'=?
R' = `"V"/"I" = 4/0.4` = 10 Ω
(b) R1 = 20 Ω; R' = 10 Ω
`1/"R'" = 1/"R" + 1/"R"_1`
`1/10 = 1/"R" + 1/20`
`1/"R" = 1/10 - 1/20`
`1/"R" = (2 - 1)/20`
`1/"R" = 1/20`
R = 20 Ω
(c) R = 20 ohm; V = 4 V
I = `"V"/"R" = 4/20` = 0.2 A
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