Question

In the network shown in figure, the equivalent resistance between points X and Y will be ______ .(A) r
(B) r/2(C) 2r
(D) r/3

Answer 1

if we arrange a proper way , we will get circuit as shown in figure.

now , equivalent resistance of AD , CF is R'
R' = r × r/(r + r) = r/2

equivalent resistance of CF , EB is R"
R" = r × r/(r + r) = r/2

R' and R" are in series combination, so
R"' = r/2 + r/2 = r

finally R"' and AC, EB are in parallel combination so, Req = r × r/(r + r) = r/2

hence, option (B) is correct