Practice portal › Current Electricity › Combination of Resistors
Asked in RS Academy GUJCET booklet · Wires bent into shapes
Given: the whole ring is 10 Ω at 1 Ω m⁻¹, so its circumference is 10 m.
Idea: A and B split the ring into two arcs, and these two arcs are in parallel between A and B.
Let one arc have resistance x; the other then has 10-x.
(x(10-x))/(10)=2.4, so x²-10x+24=0.
(x-4)(x-6)=0: the arcs are 4 Ω and 6 Ω, that is 4 m and 6 m of wire.
The shorter arc AB is 4 m long.
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