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


20