In the circuit shown, the value of each resistance is $r$, then equivalent resistance of circuit between points $A$ and $B$ will be
A$(4/3) r$
B$3r / 2$
C$r / 3$
D$8r / 7$
AIPMT 1990, Medium
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D$8r / 7$
d (d) The given circuit can be simplified as follows.
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