Calculate the ratio of the equivalent resistance of the above two wires in parallel combination to that in series combination.
The resistance of the two wires are
R1 = 2Ω and R2 = 8Ω
When they are connected in series.
Equivalent resistance = R1 + R2
⇒ Req = 2 + 8 = 10 Ω.
Req in series = 10 Ω.
When they are connected in parallel.
Equivalent resistance=
⇒
⇒
⇒
Req in Parallel = 8/5 Ω.
Ratio of Parallel to series =
Hence the ratio of the Equivalent resistances in parallel to series is 4/25