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# Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 7. The resistance of each edge is R

$\begin {array} {1 1} (A)\;\large\frac{R}{7} & \quad (B)\;\large\frac{6R}{7} \\ (C)\;\large\frac{5R}{6} & \quad (D)\;\large\frac{4R}{3} \end {array}$

The question seems complicated but can be easily simplified if one keeps a track
of all the connections and identify the equipotential points.
Here 2, 4 and 5 are equipotential. Also 3, 6 and 8 are equipotential.
Representing the above points in a simple linear potential diagram results in the
following picture. Here, each connection corresponds to a resistance R
This is a very powerful technique. Student is expected to be thorough with its use.
Ans : (C)
edited Mar 14, 2014