The effective resistance of a parallel connection that consists of four wires of equal legth, equal area of cross-section and same material is 0-25 Ω. What will be the effective resistance if they are connected in series?
For four identical resistors in parallel, the effective resistance is:
R/4 = 0.25 ⇒ R = 1Ω
In series, total resistance is:
R series= 4R = 4 × 1 = 4Ω
Thus, the correct answer is (a) 4 Ω.
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Given that four wires of equal length, cross-sectional area and material are connected in parallel and their effective resistance is 0.25 Ω, we need to determine their effective resistance when connected in series.
Let the resistance of each wire be R. Since they are connected in parallel, the effective resistance
parallel
R parallel is given by:
1/Rparallel = 1/R +1/R + 1/R
1/0.25 = 4/R
R = 1Ω
So, each individual wire has a resistance of 1 Ω.
When connected in series, the total resistance is simply the sum of the individual resistances:
Rseries = R +R + R + R = 1 + 1 + 1 + 1 = 4Ω
Correct option: (a) 4 Ω.